Diffusion of Solids in Liquids – Chemistry Project

 

S.No. Contents II Page No.
I. Introduction 4
II. Objective 5
III. Experiment 1 6
IV. Experiment 2 7
V. Experiment 3 9
VI. Result 11
VII. Bibliography 12

INTRODUCTION

When substances are brought in contact with each other they intermix, this property is known as Diffusion. This property of diffusion takes place very rapidly in case of gases and to a lesser extent in case of liquids, whereas solids do not show this process of diffusion with each other. But what we can observe in case of solids is that the diffusion of solids in liquids takes place at a very slow rate.

If a solid is kept in contact with an excess of solvent in which it is soluble, some portion of the solid gets dissolved. We know that this process is known as dissolution of a solid in liquid and this process has taken place due to the diffusion of solid particles into liquid.

Molecules of solute are in constant random motion due to the collision between molecules of solute and that of the solvent.

OBJECTIVE

Rate of diffusion depends upon:-

Temperature: As temperature increases, the kinetic energy of the particles increases so the speed of particles also increases which thus increases the rate of diffusion.

Size of the particle: As the size of particle increases, rate of diffusion decreases.

Mass of the particle: As the mass of the particle increases the rate of diffusion decreases.

EXPERIMENT 1

To study diffusion when copper sulphate is brought in contact with water (liquid)

REQUIREMENTS:

Copper sulphate crystals, 100ml beaker.

PROCEDURE:

  • Ø Take about 2g of copper sulphate crystals in 100ml beaker.
  • Ø Add about 50ml of water and allow it to stand for few minutes.
  • Ø Note the development of blue colour in water.
  • Ø Allow to stand further till it is observed that all copper sulphate disappears.
  • Ø Note the blue colour change in water.

CONCLUSION:

When solids such as copper sulphate, potassium permanganate are brought in contact with liquids such as water, intermixing of substances, i.e. diffusion takes place.

EXPERIMENT 2

To study the effect of temperature on the rate of diffusion of solids in liquids

REQUIREMENTS:

Copper sulphate crystals, 200ml beaker, watch glass, wire gauge, burner, tripod stand, thermometer and stop watch.

PROCEDURE:

  • Ø Take 5g of copper sulphate each in three beakers.
  • Ø Pour 100ml of distilled water slowly in one of the beakers.
  • Ø Cover this beaker with a watch glass.
  • Ø Pour 100ml of cold water in a second beaker slowly.
  • Ø Place a third beaker containing 100ml of water on a tripod stand for heating.
  • Ø Observe the diffusion process which begins in all the beakers.
  • Ø Record the time taken for the dissolution of copper sulphate in all the three cases.

OBSERVATIONS:

S.No. Temperature of water Time Taken in Minutes
1. 25 0C 15 Min.
2. 10 0C 20 Min.
3. 70 0C 10 Min.

CONCLUSION:

The Rate of diffusion of copper sulphate in water is in the order of Beaker 3 > Beaker 1 > Beaker 2. Thus, the rate of diffusion varies directly with temperature.

EXPERIMENT 3

To study the effect of size of particles on the rate of diffusion of solids in liquids

REQUIREMENTS:

Graduated 100ml measuring cylinders, copper sulphate crystals of different sizes, stop watch

PROCEDURE:

  • Ø Add 50ml of water to each of the three cylinders.
  • Ø Take 5g each of big size, medium size, small size crystals of copper sulphate and add them separately in three cylinders.
  • Ø Allow to stand for sometime.
  • Ø Note the time taken for blue colour to reach any fixed mark in each of the cylinders and note the observations.

OBSERVATION:

S.No. Crystal size Time Taken in Minutes
1. Big 20 Min.
2. Medium 15 Min.
3. Small 10 Min.

CONCLUSION:

Small particles undergo diffusion more quickly than bigger particles.

RESULT

  • Ø When solids such as copper sulphate, potassium permanganate are brought in contact with liquid such as water, intermixing of the substances, i.e. diffusion takes place.
  • Ø The rate of diffusion varies directly with temperature.
  • Ø Small particles undergo diffusion more quickly than bigger particles.

BIBLIOGRAPHY

  • NCERT CHEMISTRY XII
  • ENCARTA ENCYCLOPEDIA 2009

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Prepare Cup of Ammonium Rayon Threads from Filter Paper

 

 

S.No. Contents II Page No.
I. Introduction 4
II. Apparatus 6
III. Procedure 7
IV. Precaution 9
V. Bibliography 9

Introduction

Cellulose is nature’s own giant molecule. It is the fibrous material that every plant from seaweed to the sequoia makes by baking glucose molecules in long chains; the chains are bound together in the fibres that give plants their shape and strength. Wood has now become the main source of cellulose. Since it contains only 40% to 50% cellulose, the substance must be extracted by ‘pulping’. The logs are flaked, and then simmered in chemicals that dissolve the tarry lignin, resins and minerals. The remaining pulp, about 93% cellulose, is dried and rolled into sheets-raw material for paper, rayon and other products.

It can be obtained in 2 ways:

  1. Viscose Process: Cellulose is soaked in 30% caustic soda solution for about 3 hrs. The alkali solution is removed and the product is treated with CSi. This gives cellulose xanthate, which is dissolved in NaOH solution to give viscous solution. This is filtered and forced through a spinneret into a dilute H2SO4 solution, both of which harden the gum like thread into rayon fibres. The process of making viscose was discovered by C.F. Cross and EJ. Bevan in 1891.
  2. Cuprammonium Rayon: Cuprammonium rayon is obtained by dissolving pieces of filter paper in a deep blue solution containing tetra-ammine cupric hydroxide. The latter is obtained from a solution of copper sulphate. To it, NH4OH solution is added to precipitate cupric hydroxide, which is then dissolved in excess of NH3.

Reactions:

CUSO4+ 2NH4OH —> Cu(OH)2+ (NH4)2S04

Pale blue ppt

Cu(OH) 2 + 4NH4OH —> [Cu(NH3)4](0H) 2 + 4H2O

[Cu(NH3) 4](OH) 2 + pieces of filter paper left for 10-15 days give a viscous solution called VISCOSE.

Apparatus Required

a) Conical flask (preferably 250 ml)

b) Funnel

c) Glass rod

d) Beaker (preferably 250 ml)

e)Water bath

f) Filter paper

Chemicals Required

a) CuSO4

b) NaOH solution

c) Liquor ammonia solution

d) Dilute H2SO4

e) Whitman Paper

f) Distilled H2O

Procedure

A. Preparation of Schweitzer’s Solution:

a)     Weight of CuSO4.5H20.

b)     Transfer this to a beaker having 100ml distilled water and add 15ml of dilute H2SO4 to prevent hydrolysis of CuSO4.

c)      Stir it with a glass rod till a clear solution is obtained. Add 11ml of liquor ammonia drop by drop with slow stirring. The precipitate of cupric hydroxide is separated out.

d)    Filter the solution containing cupric hydroxide through a funnel with filter paper.

e)     Wash the precipitate of cupric hydroxide with water until the filtrate fails to give a positive test for sulphate ions with barium chloride solution.

f)       Transfer the precipitate to a beaker that contains 50ml of liquor ammonia or wash it down the funnel. The precipitate when dissolved in liquor ammonia gives a deep blue solution of tetra-ammine cupric hydroxide. This is known as SCHWEITZER’S SOLUTION.

B. Preparation of Cellulose material

a)     After weighing 2g of filter paper divide it into very fine pieces and then transfer these pieces to the tetra-ammine cupric hydroxide solution in the beaker.

b)     Seal the flask and keep for 10 to 15 days, during this period the filter paper is dissolved completely.

C. Formation of Ravon Thread

a)      Take 50ml of distilled water in a glass container. To this add 20ml of conc H2SO4 drop by drop. Cool the solution under tap water. In a big glass container pour some of the solution.

b)     Fill the syringe with cellulose solution prepared before.

c)      Place the big glass container containing H2SO4 solution produced before in ice (the reaction being spontaneous results in excess release of energy in the form of heat which makes the fibres weak and breaks them).

d)     Immerse the tip of the syringe in the solution and press gently. Notice the fibres getting formed in the acid bath. Continue to move your hand and keep pressing the syringe to extrude more fibres into the bath.

e)      Leave the fibres in solution till they decolorize and become strong enough.

f)       Filter and wash with distilled water.

Precautions

a)     Addition of excess NH3 should be avoided.

b)     Before taking the viscose in the syringe make sure that it does not contain any particles of paper, otherwise, it would clog the needle of the syringe.

c)      Addition of NH3 should be done in a fume cupboard and with extreme care. The fumes if inhaled may cause giddiness.

d)    Use a thick needle otherwise the fibres won’t come out.

Bibliography

Chemistry (Part I) –  Textbook for Class XII

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Constituents Of An Alloy – Chemistry Project

 

S.No. Contents II Page No.
I. Introduction 4
II. Material Required 5
III. Theory 6
IV. Procedure 8
V. Conclusion 10
VI. Bibliography 10

Introduction

An alloy is a homogeneous mixture of two or more metals or a metal and non-metal.

They are generally harder than their components with reduced malleability and ductility. Alloys are prepared to enhance certain characteristics of the constituent metals, as per requirement.

In this project, we shall qualitatively analyze the chemical composition of two alloys:

MATERIALS REQUIRED

1) BRASS AND BRONZE PIECES

2) CHINA DISHES

3) FILTRATION APPARATUS

4) NITRIC ACID

5) HYDROGEN SULPHIDE GAS

7) AMMONIUM CHLORIDE

8)POTASSIUM FERROCYANIIDE

9) AMMONIUM SULPHIDE

10) DIL HYDROCHLORIC ACID

Theory

Brass

Brass contains Cu and Zn . Both dissolve in nitric acid.

4Zn+ 10 HNO3 –> 4Zn(NO)2+ N2O + 5HO

3Cu + 8 HNO3 –> 3Cu(NO3)2 + 4HO+2NO

Further analysis is carried out for respective ions.

Cu dissolves in H2S to give black ppt. of CuS. It is filtered to get the soln of Zinc Sulphide. It precipitates out in the form of ZnCl2 in an ammonical soln. of Ammonium chloride. The precipitate is dissolved in dilute HCl and then treated with Potassium ferrocyanide to get a bluish-white ppt. of Zn2[Fe(CN)6].

Bronze

Bronze contains Cu and Sn. Their nitrates are obtained by dissolving the sample in conc. Nitric acid. The nitrates are precipitated as sulphides by passing H2S through their solution in dil. HCl.

The CuS is insoluble in yellow ammonium sulphide, while SnS is soluble. The ppt. is separated by filtration.

The ppt. is dissolved in cone HNO3 and then Ammonium hydroxide solution is passed through it. Blue colouration confirms the presence of Cu.

The filtrate is treated with conc. HCl followed by Zinc dust to obtain SnCl2 . Then HgCl2 solution is added. Formation of slate-coloured ppt. indicates the presence of Sn.

Procedure

Brass:

1. A small piece of brass was placed in a china dish and dissolved in minimum quantity of 50% conc. H2SO4.

2. The soln. was heated to obtain a dry residue. The residue was dissolved in Dilute HCl gas was passed and a black.ppt. was observed. The soln. was filtered and the ppt. was dissolved in NH4OH soln. A blue coloration observed indicates the presence of Cu.

4.   The filtrate was tested for presence of Zn. Ammonium hydroxide and chloride solutions were added and then H2S gas was passed. A dull grey ppt. was separated and dissolved in dil. HCl. followed by addition of Potassium ferrocyanide. A bluish white ppt. confirms the presence of Zn.

Bronze:

1. The sample was dissolved in 50% HNO3 and then heated to obtain nitrates.

2. The nitrates were dissolved in dil. HCl and then precipitated as sulphides by passing H2S gas.

3. The precipitates were treated with yellow amm.sulphide.

4. The ppt. was tested for Cu as in the case of brass.

5. The filtrate was treated with conc. HCl followed by Fe dust.

6. Then HgCl2 soln. was added. Formation of a slate-coloured ppt. confirmed the presence of Sn.

Conclusion

Brass contains Copper and

Bronze contains Copper and Tin.

Bibliography

1. Comprehensive practical Chemistry- Class 12.

2. www.alloyanalyzer.niit.edu

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Compare Rate Of Fermentation Of Wheat Flour – Chemistry Project

 

S.No. Contents II Page No.
I. Objective 4
II. Introduction 5
III. Theory 7
IV. Material required 8
V. Procedure 9
VI. Observation 11
VII. Bibliography 11

OBJECTIVE

The purpose of the experiment is – to compare the rate of fermentation of the given samples of wheat flour, gram flour, rice flour and potatoes.

I became interested in this idea when I saw some experiments on fermentation and wanted to find out some scientific facts about fermentation. The primary benefit of fermentation is the conversion of sugars and other carbohydrates ,e.g., converting juice into wine, grains into beer, carbohydrates into carbon dioxide to leaven bread, and sugars in vegetables into preservative organic acids.

INTRODUCTION

Fermentation typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions. A more restricted definition of fermentation is the chemical conversion of sugars into ethanol. The science of fermentation is known as zymology. Fermentation usually implies that the action of microorganisms is desirable, and the process is used to produce alcoholic beverages such as wine, beer, and cider. Fermentation is also employed in preservation techniques to create lactic acid in sour foods such as sauerkraut, dry sausages, and yoghurt, or vinegar for use in pickling foods.

Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria or a combination thereof, under anaerobic conditions. A more restricted definition of fermentation is the chemical conversion of sugars into ethanol. The science of fermentation is known as zymology.

Fermentation usually implies that the action of microorganisms is desirable, and the process is used to produce alcoholic beverages such as wine , beer, and cider. Fermentation is also employed in preservation techniques to create lactic acid in sour foods such as sauerkraut , dry sausages,  and yogurt, or vinegar (acetic acid) for use in pickling foods.

Uses

Food fermentation has been said to serve five main purposes:

#  Enrichment of the diet through development of a diversity of flavours, aromas, and textures in food substrates

#  Preservation of substantial amounts of food through lactic acid, alcohol, acetic acid and alkaline fermentations

#  Biological enrichment of food substrates with protein, essential amino acids, essential fatty acids, and vitamins

#  Elimination of ant nutrients.

#  A decrease in cooking times and fuel requirements

Theory

Wheat flour, gram flour, rice flour and potatoes contains starch as the major constituent. Starch present in these food materials is first brought into solution. In the presence of enzyme diastase, starch undergoes fermentation to give maltose.

Starch gives blue-violet colour with iodine whereas product of fermentation starch do not give any characteristic colour. When the fermentation is complete the reaction mixture stops giving blue-violet colour with iodine solution.

By comparing the time required for completion of fermentation of equal amounts of different substances containing starch the rates of fermentation can be compared. The enzyme diastase is obtained by germination of moist barley seeds in dark at 15 degree celsius. When the germination is complete the temperature is raised to 60 degree celsius to stop further growth. The seeds are crushed into water and filtered. The filtrate contains enzyme diastase and is called malt extract.

MATERIALS REQUIRED

#   Conical flask

#   Test tube

#   Funnel

#   Filter paper

#   Water bath

#   1 % Iodine solution

#   Yeast

#   Wheat flour

#   Gram flour

#   Rice flour

#   Potato

#   Aqueuos NaCl solution

PROCEDURE

#   Take 5 gms of wheat flour in 100 ml conical flask and add 30 ml of distilled water.

#   Boil the contents of the flask for about 5 minutes

#   Filter the above contents after cooling, the filtrate obtained is wheat flour extract.

#   To the wheat flour extract. taken in a conical flask.

Add 5 ml of 1% aq. NaCl solution.

#    Keep this flask in a water bath maintained at a temperature of 50-60 degree celsius. Add 2 ml  of malt extract.

#   After 2 minutes take 2 drops of the reaction mixture and add to diluted iodine solution.

#   Repeat step 6 after every 2 minutes. When no bluish colour is produced the fermentation is complete.

#   Record the total time taken for completion of fermentation.

#   Repeat the experiment with gram flour extract, rice flour extract, potato extract and record the observations

OBSERVATIONS

Time required for the fermentation—

# Wheat flour — 10 hours

#  Gram flour –  12.5 hours

#  Rice flour — 15 hours

#  Potato — 13 hours

BIBLIOGRAPHY

#   Chemistry manual

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Commercial Antacid – Chemistry Project

 

S.No. Contents II Page No.
I. Introduction 4
II. Requirements 6
III. Procedure 7
IV. Observation 10
V. Conclusion 13
VI. Bibliography 13

INTRODUCTION

An Antacid is any substance, generally a base or basic salt, which neutralizes stomach acidity. They are used to relieve acid indigestion, upset stomach, sour stomach, and heartburn.

ACTION MECHANISM

Antacids perform a neutralization reaction, i.e. they buffer gastric acid, raising the pH to reduce acidity in the stomach. When gastric hydrochloric acid reaches the nerves in the gastrointestinal mucosa, they signal pain to the central nervous system. This happens when these nerves are exposed, as in peptic ulcers. The gastric acid may also reach ulcers in the oesophagus or the duodenum.

Other mechanisms may contribute, such as the effect of aluminium ions inhibiting smooth muscle cell contraction and delaying gastric emptying.

INDICATIONS

Antacids are taken by mouth to relieve heartburn, the major symptom of gastro oesophageal reflux disease, or acid indigestion. Treatment with antacids alone is symptomatic and only justified for minor symptoms. Peptic ulcers may require H2-receptor antagonists or proton pump inhibitors.

The utility of many combinations of antacids is not clear, although the combination of magnesium and aluminium salts may prevent alteration of bowel habits.

INTERACTIONS

Altered pH or complex formation may alter the bioavailability of other drugs, such as tetracycline. Urinary excretion of certain drugs may also be affected.

PROBLEMS WITH REDUCED STOMACH ACIDITY

Reduced stomach acidity may result in an impaired ability to digest and absorb certain nutrients, such as iron and the B vitamins. Since the low pH of the stomach normally kills ingested bacteria, antacids increase the vulnerability to infection. It could also result in reduced bioavailability of some drugs. For example, the bioavailability of ketoconazole (antifungal) is reduced at high intragastric pH (low acid content).

SOME FAMOUS ANTACID BRANDS

1. Alka-Seltzer – NaHCO3 and/or KHCO3

2. Equate – Al(OH)3 and Mg(OH)2

3. Gaviscon – Al(OH)3

4. Maalox (liquid) – Al(OH)3 and Mg(OH)2

5. Maalox (tablet) – CaCO3

6. Milk of Magnesia – Mg(OH)2

7. Pepto-Bismol – HOC6H4COO

8. Pepto-Bismol Children’s – CaCO3

9. Rolaids – CaCO3 and Mg(OH)2

10. Tums – CaCO3

11. Mylanta

DRUG NAMES

Some drugs used as antacids are :

1. Aluminium hydroxide

2. Magnesium hydroxide

3. Calcium carbonate

4. Sodium bicarbonate

5. Bismuth subsalicylate

6. Histamine

7. Cimetidine

8. Ranitidine

9. Omeprazole

10. Lansoprazole

REQUIREMENTS :

  • Burettes
  • Pipettes
  • Titration flasks
  • Measuring flasks
  • Beakers
  • Weight box
  • Fractional weights
  • Sodium hydroxide
  • Sodium carbonate
  • Hydrochloric acid
  • Phenolphthalein.

PROCEDURE :

1. Prepare 1 litre of approximately  HCl solution by diluting 10 ml of the concentrated acid for one litre.

2. Similarly, make 1 litre of approximately NaOH solution by dissolving4.0g of NaOH to prepare one litre of solution.

3. Prepare  Na2CO3 solution by weighing exactly 1.325 g of anhydrous sodium carbonate and then dissolving it in water to prepare exactly 0.25 litres (250 ml) of solution.

4. Standardize the HCl solution by titrating it against the standard Na2CO3 solution using methyl orange as indicator.

5. Similarly, standardize NaOH solution by titrating it against standardized HCl solution using phenolphthalein as indicator.

6. Powder the various samples of antacid tablets and weigh 1.0 g of each.

7. Add a specific volume of standardised HCl to each of the weighed sample is taken in conical flasks. The acid should be in slight excess, so that it can neutralize all the alkaline component of the tablet.

8. Add 2 drops of phenolphthalein and warm the flask till most of powder dissolves. Filter off the insoluble material.

9. Titrate this solution against the standardised NaOH solution, till a permanent pinkish tinge is obtained. Repeat this experiment with different antacids.

OBSERVATIONS:

Standardisation of HCl solution :

Volume of Na2CO3 solution taken = 20.0 ml

S No. of obs. Burette readings

Initial       Final

Volume of acid used
1.

2.

3.

4.

5.

0 ml          15.0 ml

0 ml          15.1 ml

0 ml          15.0 ml

0 ml          15.0 ml

0 ml          15.0ml

15.0 ml

15.1 ml

15.0 ml

15.0 ml

15.0 ml

Concordant volume = 15.0 ml

Applying normality equation,

N1V1 = N2V2

N1 * 15.0 =  * 20

Normality of HCl, N1 = = 0.133 N

Standardisation of NaOH solution :

Volume of the given NaOH solution taken = 20.0 ml

S No. of obs. Burette readings

 Initial     Final

    

Volume of acid used
1.

2.

3.

4.

5.

0 ml          26.5 ml

0 ml          26.8 ml

0 ml          26.6 ml

0 ml          26.6 ml

0 ml          26.6ml

26.5 ml

26.8 ml

26.6 ml

26.6 ml

26.6 ml

Concordant volume = 26.6 ml

Applying normality equation,

N1V1 = N2V2

0.133 x26.6 = N2x20

Normality of NaOH = = 0.176 N

Analysis of antacid tablet :

Weight of antacid tablet powder = 1.0 g

Volume of HCl solution added = 20.0 ml

Antacid Vol. Of NaOH soln. Used to neutralise unused HCl Vol. Of HCl soln. Used to neutralise 1.0 g of antacid matter
1. Gelusil

2. Digene

3. Aludrox

4. Logas

5. Ranitidine

6. Ocid 20

12.1 ml

16.0 ml

19.3 ml

24.3 ml

21.4 ml

22.7 ml

12.0 ml

16.2 ml

18.9 ml

24.4 ml

21.7 ml

21.9 ml

CONCLUSION :

The antacid which has maximum volume of HCl is used for neutralizing i.e. Ocid 20 is more effective.

BIBLIOGRAPHY

1. WEBSITES :

  • www.pharmaceutical-drugmanufacturers.com

2. BOOKS :

  • Comprehensive Practical Manual for class XII
  • Pradeep’s New Course Chemistry
  • NCERT Class XII Part II

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Analysis Of Different Brands Of Cold Drinks – Chemistry Project

 

S.No. Contents II Page No.
I. Introduction 4
II. Theory 5
III. Apparatus 6
IV. Detection of pH 9
V. Test for Carbon Dioxide 10
VI. Test for Glucose 11
VII. Test for Alcohol 13
VIII. Test for Sucrose 15
IX. Result 17
X. Conclusion 18
XI. Bibliography 20

INTRODUCTION

The era of cold drinks began in 1952 but the indianization of industry marked its beginning with launching of limca and goldspot by parley group of companies. Since, the beginning of cold drinks was highly profitable and luring, many multinational companies launched their brands in India like pepsi and coke.

Now days, it is observed in general that majority of people viewed Sprite, Miranda, and Limca to give feeling of lightness, while Pepsi and Thumps Up to activate pulse and brain.

Theory

Cold drinks of different brands are composed of alcohol, carbohydrates, carbon dioxide, phosphate ions etc. These soft drinks give feeling of warmth, lightness and have a tangy taste which is liked by everyone. Carbon dioxide is responsible for the formation of froth on shaking the bottle.

The carbon dioxide gas is dissolved in water to form carbonic acid which is also responsible for the tangy taste. Carbohydrates are the naturally occurring organic compounds and are major source of energy to our body. General formula of carbohydrates is

CX (H2O)Y.

On the basis of their molecule size carbohydrates are classified as:-

Monosaccharide, Disaccharides and Polysaccharides. Glucose is a monosaccharide with formula C6H12O6 .It occurs in Free State in the ripen grapes in bones and also in many sweet fruits. It is also present in human blood to the extent of about 0.1%. Sucrose is one of the most useful disaccharides in our daily life. It is widely distributed in nature in juices, seeds and also in flowers of many plants. The main source of sucrose is sugar cane juice which contain 15-20 % sucrose and sugar beet which has about 10-17 % sucrose. The molecular formula of sucrose is C12H22O11. It is produced by a mixture of glucose and free dose. It is non-reducing in nature whereas glucose is reducing. Cold drinks are a bit acidic in nature and their acidity can be measured by finding their pH value. The pH values also depend upon the acidic contents such as citric acid and phosphoric acid.

APPARATUS

  • Test tube
  • Test tube holder
  • Test tube stand
  • Stop watch
  • Beaker
  • Burner
  • pH paper tripod stand
  • China dish
  • Wire gauge
  • Water bath
  • Iodine solution
  • Potassium  iodine
  • Sodium hydroxide
  • Fehling’s A & B solution
  • Lime water
  • Concentrated HNO3
  • Benedict solution
  • Ammonium molybdate

DETECTION OF PH

1-2 drops of the sample of cold drink of each brand was taken and put on the pH paper. The change in the color of pH paper was noticed and was compared with the standard pH scale.

OBSERVATION

SERIAL NO NAME OF

DRINK

COLOUR CHANGE PH VALUE
1 COCA COLA PINK 1-2
2 SPRITE ORANGE 3
3 LIMCA PINKISH 3-4
4 FANTA LIGHT DRINK 2-3

INFERENCE

Soft drinks are generally acidic because of the presence of citric acid and phosphoric acid. pH values of cold drink of different brands are different due to the variation in amount of acidic contents.

TEST FOR CARBON DIOXIDE

EXPERIMENT

As soon as the bottles were opened, one by one the sample was passed through lime water. The lime water turned milky.

OBSERVATON

SR. NO NAME OF THE DRINK TIME TAKEN (SEC.) CONCLUSION
1 COCA COLA 26.5 CO2 IS  PRESENT
2 SPRITE 21 CO2 IS  PRESENT
3 LIMCA 35 CO2 IS  PRESENT
4 FANTA 36 CO2 IS  PRESENT

INFERENCE

All the soft drinks contain dissolved carbon dioxide in water. The carbon dioxide (CO2) dissolves in water to form carbonic acid, which is responsible for its tangy taste.

CHEMICAL REACTION INVOLVED

Ca(OH)2 (s) + CO2(g) ———> CaCO3 (s) + H2O(s)

TEST FOR GLUCOSE

Glucose is a reducing sugar acid. Its presence is detected by the following test:-

1. BENIDICTS’S SOLUTION TEST:-

A small sample of cold drink of different brands was taken in a test tube and a few drops of Benedict’s reagent were added. The test tube was heated for few seconds. Formation of reddish color confirms the presence of glucose in cold drinks.

OBSERVATON

SR. NO NAME OF THE DRINK OBSERVATION CONCLUSION
1 COCA COLA REDDISH COLOUR GLUCOSE PRESENT
2 SPRITE REDDISH COLOUR GLUCOSE PRESENT
3 LIMCA REDDISH COLOUR GLUCOSE PRESENT
4 FANTA REDDISH COLOUR GLUCOSE PRESENT

INFERENCE

All the samples gave positive test for glucose with Benedict’s reagent. Hence all the drinks contain glucose.

2. FEHLING’S SOLUTION TEST

A small sample of cold drink of different brands was taken in a test tube and a few drops of Fehling’s A solution and Fehling’s B solution was added in equal amount. The test tube was heated in a water bath for 10 minutes. Appearance of brown precipitate confirms the presence of glucose in cold drinks.

OBSERVATON

SR. NO NAME OF THE DRINK OBSERVATION CONCLUSION
1 COCA COLA Reddish Brown Precipitate GLUCOSE PRESENT
2 SPRITE Reddish Brown Precipitate GLUCOSE PRESENT
3 LIMCA Reddish Brown Precipitate GLUCOSE PRESENT
4 FANTA Reddish Brown Precipitate GLUCOSE PRESENT

INFERENCE

All the samples give positive test for glucose with Fehling’s solutions (A&B).Hence all the cold drinks contain glucose.

TEST FOR PHOSPHATE

Sample of each brand of cold drink was taken in a separate test tube and ammonium molybdate followed by concentrated nitric acid (HNO3) was added to it, the solution was taken heated and the color of the precipitate confirms the presence of phosphate ions.

OBSERVATON

SR. NO NAME OF THE DRINK OBSERVATION CONCLUSION
1 COCA COLA CANARY-YELLOW PPT PHOSPHATE IS PRESENT
2 SPRITE CANARY-YELLOW PPT PHOSPHATE IS PRESENT
3 LIMCA CANARY-YELLOW PPT PHOSPHATE IS PRESENT
4 FANTA CANARY-YELLOW PPT PHOSPHATE IS PRESENT

INFERENCE

All the soft drinks contain phosphate ions which are detected by the presence of phosphate when canary yellow obtained.

CHEMICAL REACTION INVOLVED

NaHPO4 + 12 (NH4)2MoO4 + 21HNO3 +3H——>(NH4)3PO4.12MoO3 +21HN4NO3 +12H2O

TEST FOR ALCOHOL

Samples of each brand of cold drinks are taken in sample test tube and iodine followed by potassium iodide and sodium hydroxide (NaOH) solution is added to each test tube. Then the test tube are heated in hot water bath for 30 minutes yellow colored precipitate confirmed the presence of alcohol in cold drinks

OBSERVATON

SR. NO NAME OF THE DRINK OBSERVATION CONCLUSION
1 COCA COLA YELLOW PPT ALCOHOL  IS PRESENT
2 SPRITE YELLOW PPT ALCOHOL  IS  PRESENT
3 LIMCA YELLOW PPT ALCOHOL  IS PRESENT
4 FANTA YELLOW PPT ALCOHOL  IS PRESENT

INFERENCE

All the Brands of Cold Drinks Contain Alcohol.

CHEMICAL REACTION INVOLVED

CH3CH2OH +4I2+ 6NaOH——>CHI3 + HCOONa +5NaI +5H2O

TEST FOR SUCROSE

5 ml samples of each brand of cold drinks was taken in a china dish and heated very strongly until changes occur. Black colored residue left confirms the presence of sucrose in cold drinks.

OBSERVATON

SR. NO NAME OF THE DRINK OBSERVATION CONCLUSION
1 COCA COLA BLACK RESIDUE SUCROSE  IS PRESENT
2 SPRITE BLACK RESIDUE SUCROSE  IS PRESENT
3 LIMCA BLACK RESIDUE SUCROSE  IS PRESENT
4 FANTA BLACK RESIDUE SUCROSE  IS PRESENT

INFERENCE

All the brands of cold drinks contain sucrose. But amount of sucrose varies in each brand of drink. Fanta contained highest amount of sucrose.

RESULT

After conducting several tests, it was concluded that the different brands of cold drinks namely

  1. Coca cola
  2. Sprite
  3. Limca
  4. Fanta

All contains glucose, alcohol sucrose, phosphate, ions and carbon dioxide. All are acidic in nature. On comparing the pH value of different brands coca cola is most acidic and Limca is least acidic of all the four brands taken.

pH value of coca cola is nearly equal to disinfectant which is harmful for body.

CARBON DIOXIDE

AMONG THE FOUR SAMPLES OF COLD DRINKS TAKEN –SPRITE HAS MAXIMUM AMOUNT OF DISSOLVED CARBON DIOXIDE AND FANTA HAS MINIMUM AMOUNT OF DISSOLVED CARBON DIOXIDE.

CONCLUSION

DISADVANTAGES OF COLD DRINKS

  1. Soft drinks are little more harmful than sugar solution. As they contain sugar in large amount which cause “diabetes”.
  2. Soft drinks can cause weight gain as they interfere with the body’s natural ability to suppress hunger feeling.
  3. Soft drinks have ability to dissolve the calcium so they are also harmful for our bones.
  4. Soft drinks contain “phosphoric acid” which has a pH of 2.8. So they can dissolve a nail in about 4 days.
  5. For transportation of soft drinks syrup the commercial truck must use the hazardous matter place cards reserved for highly consive material.
  6. Soft drinks have also ability to remove blood so they are very harmful to our body.

USES OF COLD DRINKS

  1. Cold drinks can be used as toilet cleaners.
  2. They can remove rust spots from chrome car bumper.
  3. They clean corrosion from car battery terminals.
  4. Soft drinks are used as an excellent ‘detergent’ to remove grease from clothes.
  5. They can lose a rusted bolt.

BIBLIOGRAPHY

  • NCERT CHEMISTRY XII
  • ENCARTA ENCYCLOPEDIA 2009

You can find other Chemistry Projects here.

Change in EMF of a Daniel Cell – Chemistry Project

 

S.No. Contents II Page No.
I. Objective 3
II. Theory 3
III. Material and Equipment 8
IV. Procedure 9
V. Observation 10
VI. Conclusion 11
VII. Bibliography 12

Objective

The goal of this project Is to study the change in E.M.F. of a Daniel cell Due to various factors such as  Change in concentration, temperature And Area of electrodes.

Theory

The Daniell cell was invented in 1836 by John Frederic Daniell, a British chemist and meteorologist, and consisted of a copper pot filled with a copper sulphate solution, in which was immersed an unglazed earthenware container filled with sulphuric acid and a zinc electrode. He was searching for a way to eliminate the hydrogen bubble problem found in the Voltaic pile, and his solution was to use a second electrolyte to consume the hydrogen produced by the first. The Daniell cell was a great improvement over the existing technology used in the early days of battery development. A later variant of the Daniell cell called the gravity cell or crowfoot cell was invented in the 1860s by a Frenchman named Callaud and became a popular choice for electrical telegraphy.

When an external circuit is connected, the chemical equation for the zinc side (anode) half cell is:

Zn (s) Zn2+ (aq) + 2 e

For the copper sulphate side (cathode) half cell:

Cu2+ (aq) + 2 e Cu (s)

Therefore, the overall reaction of the Daniel cell is:

Zn (s) + Cu2+ (aq) Zn2+ (aq) + Cu (s)

It is an arrangement to convert the chemical energy of the redox reaction into electric energy.

Zn (s) + Cu2+ (aq) Zn2+ (aq) + Cu (s)

Features of Daniel Cell:-

v Zinc rod at which oxidation occurs is called the anode while the copper rod at which the reduction takes place is called cathode.

v The overall reaction occurring in electrochemical cell is due to two half-cell reaction, one occurring in each beaker.

v The half-cell reaction occurring at anode is called oxidation -half cell reaction while the occurring at cathode is called reduction.

v The two half-cell reactions always take place simultaneously i.e. . .  Half cell reaction cannot take place immediately.

v Since electrons are produced at zinc electrode, it is rich in electrons and pulls these electrons into the external circuit and hence acts as negative pole. The copper electrode on the other hand is deficient in electrons and thus pulls the electrons from the external circuit and act as positive pole.

The electrons flow from negative pole to positive  pole in the external circuit. However, conventionally the current is said to flow in opposite direction i.e. from positive pole to negative pole in the external circuit.

The concentration of copper sulphate solution decreases with passage of time as the cell operates, consequently the current fall with passage of time.

v      Salt Bridge  :-

It consists of a tube filled with semi-solid paste obtained by adding gelative or agar to the solution of strong electrolyte  such as NaCl , NH4NO3.KNO3 etc, which does not change chemically during the process.

v Function of salt bridge:-

To complete the electrical circuit by allowing the solution to flow from one solution to another without mixing the two solutions.

To maintain electrical neutrality of solution in two half-cells.

v EMF of Cells:-

When a current flows through two points a potential difference generated by a cell when the cell draws no current is called EMF.

Materials and Equipment

To do this experiment we will need the following materials and equipment:

v  Two beakers.

v  Zinc and Copper plate.

v  Filter paper.

v  Voltmeter.

v  Connecting wires.

v  Card board.

v  KNO3 solution.

v  1 M, 0.1M, 0.01 M  solution of :-

  1. a. CuSO4
  2. b. ZnSO4

Procedure

I. Take two beakers and pour the required chemicals in respective beaker and mark them for identification.

II. Take two square to slide in and connecting wire to their screw.

III. Connect negative of the voltmeter to the anode and its positive to  the cathode

IV. Take filter paper long enough to dip into both the solution.  Dip the filter paper in  KNo3 solution and put it as a salt bridge.

V. Put on the electrode voltmeter set up.  Note the reading quickly and then put of the electrode voltmeter set up.

VI. For measuring variation with temperature with change in area of electrode use the different size of electrode and then do step 5 again.

VII. For measuring variation with temperature heat the solution and then do step 5 again.

VIII. For measuring variations with change in concentration of electrolyte ,use  the electrolytes of different molarity and then do step 5 again.

Observations:-

v Electrode Potential of  Zinc =…………….V

v Electrode Potential of Copper=…………V

v     Variation with Concentration:-

Molarity  of CuSO4(M) Molarity of ZnSO4(M) Voltmeter Reading (V)

v     Variation with change in area of electrodes:-

With increase in area or decrease in area of electrode EMF of cell remains same.

v     Variation with temperature:-

Cuso4(.c) ZnSo4(.c) Voltmeter Reading(V)

Conclusions:-

v The EMF varies non-linearly with change in concentration of reactants.

v Increase in concentration of ions in anode half-cell decreases EMF and vice-verse.

v The EMF is independent of area of electrode.

v The EMF increases with increase in temperature.

BIBLIOGRAPHY

  • NCERT CHEMISTRY XII
  • ENCARTA ENCYCLOPEDIA 2009

You can find other Chemistry Projects here.

Caffeine in Tea Samples

 

S.No. Contents II Page No.
I. Introduction 4
II. Theory 6
III. Experiment 8
IV. Observation 10
V. Result 11
VI. Bibliography 12

Introduction

Tea is the most commonly and widely used soft beverage in the household. It acts as a stimulant for central nervous system and skeletal muscles. That is why tea removes fatigue, tiredness and headache. It also increases the capacity of thinking. It is also used for lowering body temperature. The principal constituent of tea, which is responsible for all these properties, is the alkaloid-caffeine. The amount of caffeine in tea leavers varies from sample to sample.

Originally it was thought that caffeine is responsible for the taste and flavour of tea. But pure caffeine has been found to be a tasteless while substance. Therefore, the taste and flavour of tea is due to some other substance present in it. There is a little doubt that the popularity of the xanthenes beverages depends on their stimulant action, although most people are unaware of any stimulation. The degree to which an individual is stimulated by given amount of caffeine varies from individual to individual.

For example, some people boast their ability to drink several cups of coffee in evening and yet sleep like a long, on the other hand there are people who are so sensitive to caffeine that even a single cup of coffee will cause a response boarding on the toxic.

The xanthene beverages also create a medical problem. They are dietary of a stimulant of the CNS. Often the physicians face the question whether to deny caffeine-containing beverages to patients or not. In fact children are more susceptible than adults to excitation by xanthenes.

For this reason, tea and coffee should be excluded from their diet. Even cocoa is of doubtful value. It has a high tannin content may be as high as 50 mg per cup.

After all our main stress is on the presence of caffeine in xanthene beverages and so in this project we will study and observe the quantity of caffeine varying in different samples of tea leaves.

Theory

The most important methylated alkaloid that occurs naturally is caffeine. Its molecular formula is CsH10N4O2. Its IUPAC name is 1, 3, 7-trimethylxanthene and common name is 1-methylated thiobromine.

Purely it is white, crystalline solid in the form of needles. Its melting point is 1230c. It is the main active principle component of tea leaves. It is present in tea leaves up to 3% and can be extracted by first boiling the tea leaves with water which dissolves many glycoside compounds in addition to caffeine. The clear solution is then treated with lead acetate to precipitate the glycoside compounds in the form of lead complex. The clear filtrate is then extracted with extracts caffeine because it is more soluble in it then water.

Uses of Caffeine :

1. In medicine, it is used to stimulate, central nervous system and to increase flow of urine.

2.  Because of its stimulating effects, caffeine has been used to relieve fatigue. But it is dangerous and one may collapse if not consumes it under certain limit.

3.  Caffeine is also used in analgesic tablets, as it is believed to be a pain reliever. It is also beneficial in migraines.

Effects of Caffeine

1. It is psycho – stimulant.

2.  It improves physical and mental ability.

3.  Its effect in learning is doubtful but intellectual performance may improve where it has been used to reduce fatigue or boredom.

4.When administered internally, it stimulates heart and nervous system and also acts as diuretic. On the contrary their excessive use is harmful to digestion and their long use leads to mental retardation.

Procedure

  1. First of all, 50 grams of tea leaves were taken as sample and 150 ml of water was added to it in a beaker.
  2. Then the beaker was heated up to extreme boiling.
  3. The solution was filtered and lead acetate was added to the filtrate, leading to the formation of a curdy brown coloured precipitate.
  4. We kept on adding lead acetate till no more precipitate has been formed.
  5. Again solution was filtered.
  6. Now the filtrate so obtained was heated until it had become 50 ml.
  7. Then the solution left was allowed to cool.
  8. After that, 20 ml. of chloroform was added to it.
  9. Soon after, two layers appeared in the separating funnel.
  10. We separated the lower layer.
  11. The solution then exposed to atmosphere in order to allow chloroform to get evaporated.
  12. The residue left behind was caffeine.
  13. Then we weighed it and recorded the observations.
  14. Similar procedure was performed with different samples of tealeaves and quantity of caffeine was observed in them

OBSERVATION

I. Red Label Tea (Brooke Bond)

Weight of china dish 46.60gms
Weight of china dish with precipitate 47.20gms.
Amount of caffeine 0.60gms
2.Yellow Label Tea (Lipton)
Weight of china dish 46.60gms
Weight of china dish with precipitate 47.15gms.
Amount of caffeine 0.55gms

3.Green Label Tea (Lipton)

Weight of china dish 46.60gms.
Weight of china dish with precipitate 47.05gms.
Amount of caffeine 0.45gms.

1. Quantity of caffeine in Red label tea is 60mg. /sample of 50 gm.

2. Quantity of caffeine in yellow label tea  is  55mg./sample  of 50 gm.

3. Quantity of caffeine in green label tea is 45mg./sample of 50 gm.

Graphically plotting various tea samples in accordance with the amount of caffeine present in them we present a stunning find:

60 mg 55 mg 45 mg
RED LABEL YELLOW LABEL GREEN LABEL

RESULT

Order of quantities of caffeine in different samples of tealeaves

Heel Label > Yellow Label > ten Label

BIBLIOGRAPHY

  • NCERT CHEMISTRY XII
  • ENCARTA ENCYCLOPEDIA 2009

You can find other Chemistry Projects here.

Caesin Present In Different Samples Of Milk – Chemistry Project

 

S.No. Contents II Page No.
I. Introduction
II. Requirements
III. Theory
IV. Procedure
V. Observation
VI. Conclusion
VII. Bibliography

Introduction

Milk is a complete diet as it contains in its Minerals, Vitamins, Proteins, Carbohydrates, Fats And Water. Average composition of milk from different sources is given below:

Source Water Mineral Protein Fats Carbohydrate
of milk (%) s (%) ns(%) (%) (%)
Cow 87.1 0.7 3.4 3.9 4.9
Human 87.4 0.2 1.4 4.0 4.9
Goat 87.0 0.7 3.3 4.2 4.8
Sheep 82.6 0.9 5.5 6.5 4.5

Casein is a major protein constituent in milk & is a mixed phosphor-protein. Casein has isoelectric pH of about 4.7 and can be easily separated around this isoelectric pH. It readily dissolves in dilute acids and alkalis. Casein is present in milk as calcium caseinate in the form of micelles. These micelles have negative charge and on adding acid to milk the negative charges are neutralized.

Ca2+-Caseinate +2CH3COOH(aq)-Caesin+(CH3COO)2Ca

REQUIREMENTS

>                 Beakers (250 ml)

>                 Filter-paper

>                 Glass rod

>                 Weight box

>                 Filtration flask

>                 Buchner funnel

>                 Test tubes

>                 Porcelain dish

>                 Different samples of milk

>                 1 % acetic acid solution

>                 Ammonium sulphate solution

Theory

Natural milk is an opaque white fluid. Secreted by the mammary glands of female mammal . The main constituents of natural milk are Protein, Carbohydrate, Mineral, Vitamins, Fats and Water and is a complete balanced diet. Fresh milk is sweetish in taste. However, when it is kept for long time at a temperature of 5 degree it becomes sour because of bacteria present in air . These bacteria convert lactose of milk into lactic acid which is sour in taste.    In acidic condition casein of milk starts separating out as a precipitate. When the acidity in milk is sufficient and the temperature is around 36 degree, it forms a semi-solid mass, called curd.

PROCEDURE

1. A clean dry beaker has been taken, followed by putting 20 ml of cow’s milk into it and adding 20 ml of saturated ammonium sulphate solution slowly and with stirring. Fat along with Caesin was precipitate out.

2. The solution was filtered and transferred the precipitates in another beaker. Added about 30 ml of water to the precipitate. Only Caesin dissolves in water forming milky solution leaving fat undissolved.

3. The milky solution was heated to about 40oC and add 1% acetic acid solution drop-wise, when casein got precipitated.

4. Filtered the precipitate, washed with water and the precipitate was allowed to dry.

5. Weighed the dry solid mass in a previously weighed watch glass.

6. The experiment was repeated with other samples of milk.

OBSERVATIONS

CONCLUSION

Different samples of milk contain different percentage of Caesin.

BIBLIOGRAPHY

  • NCERT CHEMISTRY XII
  • ENCARTA ENCYCLOPEDIA 2009

You can find other Chemistry Projects here.

Making Biodiesel From French Fries Oil

 

BD21295_INTRODUCTION

BD21300_TODAY

BD21300_PROPERTIES

BD21300_USES

BD21300_SAFETY

BD21300_COMPARISON TO PETROL FUELS

BD21300_CAN BIODIESEL BE PRODUCED

BD21300_PROBLEMS FACED

BD21295_PROCEDURE

BD21295_OBSERVATIONS

BD21295_PRECAUTIONS

BD21295_RESULT AND DISCUSSION

BD21295_BIBLIOGRAPHY

INTRODUCTION

Need for biodiesel:

In this advancing age, the importance of fuels is tremendous. The world runs on fuels such as petroleum and diesel. Every year, billions of tones of coal and natural gas are extracted and used up. But these, being natural resources, are nearing depletion levels. The search is on for alternative sources of fuel. This is where Biodiesel comes into the picture. Biodiesel has been around for about 100 years or so. But it is not used widely like petrol and diesel.

However, the petroleum industries were able to make inroads in fuel markets because their fuel was much cheaper to produce than the biomass alternatives. The result, for many years, was a near elimination of the biomass fuel production infrastructure.

Only recently, have environmental impact concerns and a decreasing price differential made biomass fuels such as biodiesel a growing alternative.

What is biodiesel?

imag12

Biodiesel is a renewable fuel that can be manufactured from algae, vegetable oils, animal fats or recycled restaurant greases; it can be produced locally in most countries.

Biodiesel refers to a diesel-equivalent processed fuel derived from biological sources (such as vegetable oils) which can be used in unmodified diesel-engine vehicles.

Chemically, transesterified biodiesel comprises a mix of mono-alkyl esters of long chain fatty acids.

It is distinguished from the straight vegetable oils (SVO) or waste vegetable oils (WVO) used as fuels in some diesel vehicles.

It is safe, biodegradable, non-toxic and reduces air pollutants, such as particulates, carbon monoxide and hydrocarbons.

Properties:

image12

  1. Biodiesel is a liquid which varies in color — between golden and dark brown — depending on the production feedstock.
  2. Biodiesel uncontaminated with starting material can be regarded as non-toxic.
  3. It is practically immiscible with water, has a high boiling point and low vapor pressure. Typical methyl ester biodiesel has a flash point of ~ 150 °C (300 °F).
  4. Biodiesel has a density of ~ 0.88 g/cm³, less than that of water..
  5. Biodiesel has about 5–8% less energy density , but better lubricity and more complete combustion can make the energy output of a diesel engine only 2% less per volume when compared to petro-diesel — or about 35 MJ/L
  6. The flash point of biodiesel (>150 °C) is significantly higher than that of petroleum diesel (64 °C) or gasoline (−45 °C). The gel point of biodiesel varies depending on the proportion of different types of esters contained.
  7. However, most biodiesel, including that made from soybean oil, has a somewhat higher gel and cloud point than petroleum diesel. In practice this often requires the heating of storage tanks, especially in cooler climates.

Uses:

images[4]

  1. Biodiesel can be used in pure form (B100) or may be blended with petroleum diesel at any concentration in most modern diesel engines.
  2. Blends of 20 percent biodiesel with 80 percent petroleum diesel (B20) can generally be used in unmodified diesel engines. Biodiesel can also be used in its pure form (B100), but may require certain engine modifications to avoid maintenance and performance problems.
  3. Biodiesel can also be used as a heating fuel in domestic and commercial boilers.

Safety:

Existing oil boilers may contain rubber parts and may require conversion to run on biodiesel, but the conversion process is usually relatively simple– involving the exchanging of rubber parts for synthetic ones due to biodiesel being a strong solvent.

Biodiesel will degrade natural rubber gaskets and hoses in vehicles. They should be replaced with FKM, which is nonreactive to biodiesel. However, this is more likely to occur where methanol used to catalyse the transesterification process has not been properly removed afterwards.

One should not burn B100 (pure 100% biodiesel) in an existing home heater without breaking it in, as biodiesel will dissolve coagulated heating oil, which can break off in chunks and cause problems.

The presence of water is a problem because:

  • Water reduces the heat of combustion of the bulk fuel. This means more smoke, harder starting, less power.
  • Water causes corrosion of vital fuel system components: fuel pumps, injector pumps, fuel lines, etc.
  • Water & microbes cause the paper element filters in the system to fail ( rot), which in turn results in premature failure of the fuel pump due to ingestion of large particles.
  • Water freezes to form ice crystals near 0 °C (32 °F). These crystals provide sites for nucleation and accelerate the gelling of the residual fuel.
  • Water accelerates the growth of microbe colonies, which can plug up a fuel system. Biodiesel users who have heated fuel tanks, therefore, face a year-round microbe problem.

When compared to petroleum fuels:

imag6

Biodiesel typically produces about 60% less net-lifecycle carbon dioxide emissions, as it is itself produced from atmospheric carbon dioxide via photosynthesis in plants.

However, the smog forming hydrocarbon emissions are 35% greater, and the Nitrogen Oxide emissions are also greater than those from petroleum-based diesel.

Some vehicle manufacturers are positive about the use of biodiesel, citing lower engine wear as one of the fuel’s benefits.

Biodiesel’s higher lubricity index compared to petrodiesel is an advantage and can contribute to longer fuel injector life.

Biodiesel is a better solvent than standard diesel, as it ‘cleans’ the engine, removing deposits in the fuel lines. It has been known to break down deposits of residue in the fuel lines of vehicles that have previously been run on petrodiesel.

However, this may cause blockages in the fuel injectors if an engine has been previously run on petroleum diesel for years.

Conversion to Biodiesel:

images[5]

Some operational problems were reported due to the high viscosity of vegetable oils compared to petroleum diesel fuel, which result in poor atomization of the fuel in the fuel spray and often leads to deposits and coking of the injectors, combustion chamber and valves.

Attempts to overcome these problems included heating of the vegetable oil, blending it with petroleum-derived diesel fuel or ethanol, pyrolysis and cracking of the oils.

Some International standards were set in order to regulate the quality of Biodiesel produced around the world.The standards ensure that the following important factors in the fuel production process are satisfied:

  • Complete reaction.
  • Removal of glycerin.
  • Removal of catalyst.
  • Removal of alcohol.
  • Absence of free fatty acids.
  • Low sulfur content.

Basic industrial tests to determine whether the products conform to the standards typically include gas chromatography, a test that verifies only the more important of the variables above.

Tests that are more complete are more expensive. Fuel meeting the quality standards is very non-toxic, with a toxicity rating (LD50) of greater than 50 mL/kg.

Importance of Biodiesel today:

Biodiesel is used by millions of car owners in Europe (particularly Germany).

Research sponsored by petroleum producers has found petroleum diesel better for car engines than biodiesel. This has been disputed by independent bodies, including for example the Volkswagen environmental awareness division, who note that biodiesel reduces engine wear.

Pure biodiesel produced ‘at home’ is in use by thousands of drivers who have not experienced failure, however, the fact remains that biodiesel has been widely available at gas stations for less than a decade, and will hence carry more risk than older fuels.

Many municipalities have started using 5% biodiesel (B5) in snow-removal equipment and other systems.

Biodiesel sold publicly is held to high standards set by national standards bodies.

Global biodiesel production reached 3.8 million tons in 2005. Approximately 85% of biodiesel production came from the European Union.

In the United States, biodiesel is the only alternative fuel to have successfully completed the Health Effects Testing requirements (Tier I and Tier II) of the Clean Air Act (1990).

Biodiesel is considered readily biodegradable under ideal conditions and non-toxic.

A University of Idaho study compared biodegradation rates of biodiesel, neat vegetable oils, biodiesel and petroleum diesel blends, and neat 2-D diesel fuel.

Using low concentrations of the product to be degraded (10 ppm) in nutrient and sewage sludge amended solutions, they demonstrated

mphasentrenner

Separation of droplets and solids at phase separation profiles

that biodiesel degraded at the same rate as a dextrose control and 5 times as quickly as petroleum diesel over a period of 28 days, and that biodiesel blends doubled the rate of petroleum diesel degradation through co-metabolism.

The same study examined soil degradation using 10 000 ppm of biodiesel and petroleum diesel, and found biodiesel degraded at twice the rate of petroleum diesel in soil.

In all cases, it was determined biodiesel also degraded more completely than petroleum diesel, which produced poorly degradable undetermined intermediates.

Toxicity studies for the same project demonstrated no mortalities and few toxic effects on rats and rabbits with up to 5000 mg/kg of biodiesel.

Petroleum diesel showed no mortalities at the same concentration either, however toxic effects such as hair loss and urinary discolouring were noted with concentrations of >2000 mg/l in rabbits.

Since biodiesel is more often used in a blend with petroleum diesel, there are fewer formal studies about the effects on pure biodiesel in unmodified engines and vehicles in day-to-day use.

Can Biodiesel be produced?

image4

Chemically, transesterified biodiesel comprises a mix of mono-alkyl esters of long chain fatty acids.

The most common form uses methanol to produce methyl esters as it is the cheapest alcohol available, though ethanol can be used to produce an ethyl ester biodiesel and higher alcohols such as isopropanol and butanol have also been used. Using alcohols of higher molecular weights improves the cold flow properties of the resulting ester, at the cost of a less efficient transesterification reaction.

A lipid transesterification production process is used to convert the base oil to the desired esters. Any Free fatty acids (FFAs) in the base oil are either converted to soap and removed from the process, or they are esterified (yielding more biodiesel) using an acidic catalyst.

After this processing, unlike straight vegetable oil, biodiesel has combustion properties very similar to those of petroleum diesel, and can replace it in most current uses.

A byproduct of the transesterification process is the production of glycerol. For every 1 tonne of biodiesel that is manufactured, 100 kg of glycerol are produced. Originally, there was a valuable market for the glycerol, which assisted the economics of the process as a whole. However, with the increase in global biodiesel production, the market price for this crude glycerol (containing 20% water and catalyst residues) has crashed.

  • Raw material needed for production of Biodiesel:

imag2

A variety of oils can be used to produce biodiesel. These include:

  1. Virgin oil feedstock; rapeseed and soybean oils are most commonly used, soybean oil alone accounting for about ninety percent of all fuel stocks; It also can be obtained from field pennycress and Jatropha[22] other crops such as mustard, flax, sunflower, canola, palm oil, hemp, and even algae show promise.
  2. Waste vegetable oil (WVO);
  3. Animal fats including tallow, lard, yellow grease, chicken fat,[22] and the by-products of the production of Omega-3 fatty acids from fish oil.
  4. Sewage. A company in New Zealand has successfully developed a system for using sewage waste as a substrate for algae and then producing bio-diesel.

Problems faced:

bio4

Worldwide production of vegetable oil and animal fat is not yet sufficient to replace liquid fossil fuel use.

Furthermore, some environmental groups object to the vast amount of farming and the resulting over-fertilization, pesticide use, and land use conversion that they say would be needed to produce the additional vegetable oil.

  • Many advocates suggest that waste vegetable oil is the best source of oil to produce biodiesel. However, the available supply is drastically less than the amount of petroleum-based fuel that is burned for transportation and home heating in the world.
  • It is important to note that one gallon of waste oil is not equivalent to one gallon of biodiesel
  • Although it is economically profitable to use WVO to produce biodiesel, it is even more profitable to convert WVO into other products such as soap. Therefore, most WVO that is not dumped into landfills is used for these other purposes.
  • Animal fats are similarly limited in supply, and it would not be efficient to raise animals simply for their fat. However, producing biodiesel with animal fat that would have otherwise been discarded could replace a small percentage of petroleum diesel usage.
  • Advantages of Biodiesel:

Biodiesel feedstock plants utilize photosynthesis to convert solar energy into chemical energy. The stored chemical energy is released when it is burned, therefore plants can offer a sustainable oil source for biodiesel production.

Most of the carbon dioxide emitted when burning biodiesel is simply recycling that which was absorbed during plant growth. So the net production of greenhouse gases is small. However, Biodiesel produces more NOx emissions than standard diesel fuel.

At the tailpipe, biodiesel emits 4.7% more CO2 than petroleum diesel”. However, if “biomass carbon [is] accounted for separately from fossil-derived carbon”, one can conclude that biodiesel reduces emissions of carbon monoxide (CO) by approximately 50% and carbon dioxide by 78% on a net lifecycle basis because the carbon in biodiesel emissions is recycled from carbon that was in the atmosphere, rather than the carbon introduced from petroleum that was sequestered in the earth’s crust.

Biodiesel contains fewer aromatic hydrocarbons:

benzofluoranthene: 56% reduction; Benzopyrenes: 71% reduction.

Biodiesel can reduce by as much as 20% the direct (tailpipe) emission of particulates, small particles of solid combustion products, on vehicles with particulate filters, compared with low-sulfur (<50 ppm) diesel.

Particulate emissions as the result of production are reduced by around 50%, compared with fossil-sourced diesel.

Biodiesel has a higher cetane rating than petrodiesel, which can improve performance and clean up emissions compared to crude petro-diesel (with cetane lower than 40).

Laboratory Synthesis of Bioediesel

Aim: Making Biodiesel from French fries oil

Procedure:

  • Examine the container of waste fryer oil and note its appearance. Depending upon the oil, it may also be more or less solidified, because frying oils vary widely from “lard” which is an animal fat, to lighter oils such as corn or soy oil.
  • Waste material in the used oil must be removed. For this purpose, a filter made of a piece of cloth may be used. Filter out about 200ml of the oil. Examine the filtered oil and note down its appearance.
  • Carefully pour 1 mL of the oil into a graduated cylinder. Add enough isopropanol to it to make 10 mL, cover with a piece of parafilm and invert several times to mix. Pour the resulting solution into a 25 mL Erlenmeyer flask and cover it with parafilm, too.
  • Use a small piece of pH paper to measure the pH of the solution, and note the pH in your notebook as well.
  • A solution containing 1 gram of alkali per liter of water has been made and will be put in a buret. Use this buret to add 1 mL of this alkali solution to the contents of your 25 mL Erlenmeyer, cover and mix carefully by swirling. Measure the pH with pH paper. Repeat as often as necessary to cause the pH to change to around 8 or 9. Note the total volume of alkali needed.
  • The concentration of the titrant was chosen so that the number of ml of titrant equals the number of extra grams of alkali needed to neutralize the free fatty acids. To this must be added the amount of alkali needed to catalyze the reaction.
  • If the alkali used is to be sodium hydroxide, this will be 3.5 g of NaOH per liter of oil. If potassium hydroxide is to be used, we will need 9.0 g of KOH per liter of oil.

Add the required amount of alkali.

  • Measure the amount of methanol you will need in a graduated cylinder. You’ll be assigned an amount from 10% to 20% of the oil by volume. Add that amount to a 250 mL Erlenmeyer flask and immediately cover it with a piece of parafilm so it doesn’t evaporate.
  • Carefully slide a stirring bar down the side of the flask, add the alkali from your weighing boat, and cover with the parafilm. Put the flask on the stirrer and start it mixing to dissolve the alkali. It will take a few minutes to dissolve.
  • Using a graduated cylinder, measure 200 mL of filtered oil and add it to the 250 mL flask while stirring. Re-cover with parafilm, and let it stir for 1 hour.Remove from the stirrer and pour your mix into a separatory funnel and cap. Be careful not to let the stirring bar drop into the separatory funnel. Let the mixture settle at least overnight.
  • Use the separatory funnel to drain as much of the glycerin as you can into a graduated cylinder. It tends to coat the sides of the funnel, so it may take several minutes to get it out. Note how much you have. If there is a soap layer, drain it into a separate graduated cylinder and note its volume as well. Pour the biodiesel from the top of the funnel into another graduated cylinder and note its volume.

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Intelligent micro fine filtration

  • Use pH paper to check the pH of both the top biodiesel layer and the bottom glycerin layer. If there was a soap layer, check its pH as well.
  • Fryer oils will have a specific gravity generally around 0.94-0.96, while biodiesel will have a specific gravity in the 0.86-0.89 range. We generally consider biodiesel specific gravities above 0.9 to be incompletely transesterified. you can weigh a small amount of the biodiesel using a volumetric flask to calculate the density, and from that the specific gravity.
  • Viscosity is also an important property since most applications such as diesel engines and oil furnaces use a pump to spray the fuel into the combustion chamber. Biodiesel must have a viscosity similar to petroleum diesel to be useful in the same equipment.

Precautions

  • The chemicals should be handled with care to avoid any mishaps.
  • Sodium hydroxide and potassium hydroxide can cause chemical burns, either from the solid form or the alcohol solutions. Therefore these must be used with caution.
  • Place the esters and the glycerin in the containers provided.
  • Any excess or left over vegetable oil can be put back into the Waste Fryer Oil container.
  • Any excess alcohol or lye can be thrown away.

Result and Conclusion

The oil sample thus obtained is put in a small oil lamp. It is observed that the lamp burns well with less smoke. Therefore the synthesis of biodiesel has been completed successfully.

The biodiesel produced was found to be releasing very less smoke. Therefore it is less polluting. It can even be used in the common diesel engines. This will greatly reduce the emission of CO2 and other poisonous gases as exhaust from automobiles. Mass production of biodiesel from waste oil will also reduce the amount of waste oil that is dumped in pits causing a lot of pollution.

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BIBLIOGRAPHY

  • www.franken filtertechnik kg.com/
  • www.biodiesel.com/

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