Contents                                                                            

1. Introduction 
2. Theory
3. Aim
4. Apparatus
5. Chemicals Required
6. Detection of pH
7. Test for Carbon Dioxide
8. Test for Glucose
9. Test for Phosphate
10. Test for Alcohol
11. Test for Sucrose
12. Result
13. Precautions
14. Conclusion
15. Bibliography

Introduction

The  era  of  cold  drinks  began  in  1952 but the industrialization in India 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, Fanta 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 fructose. 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.

Aim

Comparitive Study and Qualitative Analysis of different brands of Cold Drinks available in market.

Apparatus

Test Tubes

Test Tube Holder

Test Tube Stand

Stop Watch

Beaker

BunsenBurner

pH Paper

Tripod Stand

China Dish

Wire Gauge

Water Bath

Chemicals Required

Iodine Solution , Potassium Iodide , Sodium Hydroxide

Lime Water ,  Fehling’s A & B Solution , Concentrated Nitric Acid

Benedict Solution , Ammonium Molybdate

Detection Of pH

Experiment

Small samples of cold drinks of different brands were taken in a test tube and put on the pH paper. The change in colour of pH paper was noticed and was compared with standard pH scale.

Observation

Sr. No.	Name Of The Drink	Colour Change	pH Value
1.	Coca Cola	Pinkish	2 – 3
2.	Sprite	Dark Orange	3
3.	Limca	Light Orange	4
4.	Fanta	Orange	3–4

 

Inference

Soft Drinks are generally acidic because of the presence of citric acid and phosphoric acid. pH values of  cold  drinks  of  different brand  are  different  due  to  the  variation  in  amount  of  acidic content.

Test For Carbon Dioxide

Experiment

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

Observation

Sr. No.	Name Of The Drink	Time taken (sec)	Conclusion
1.	Coca Cola	28	CO2 is present
2.	Sprite	20	CO2 is present
3.	Limca	38	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

Ca(OH)₂ (s) + CO₂ (g) → CaCO₃ (s) + H₂O(l)

Test For Glucose

Experiment

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

1. Benedict’s Reagent Test

Small samples of cold drinks of different brands were 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 confirmed the presence of glucose in cold drinks.

Observation

Sr. No.	Name Of The Drink	Observation	Conclusion
1.	Coca Cola	Reddish Colour Precipitate	Glucose is Present
2.	Sprite	Reddish Colour Precipitate	Glucose is Present
3.	Limca	Reddish Colour Precipitate	Glucose is Present
4.	Fanta	Reddish Colour Precipitate	Glucose is 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

Small samples of cold drinks of different brands were 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 water bath for 10 minutes. Appearance of brown precipitate confirmed the presence of glucose in cold drinks.

Observation

Sr. No.	Name Of The Drink	Observation	Conclusion
1.	Coca Cola	Reddish Brown Precipitate	Glucose is Present
2.	Sprite	Reddish Brown Precipitate	Glucose is Present
3.	Limca	Reddish Brown Precipitate	Glucose is Present
4.	Fanta	Reddish Brown Precipitate	Glucose is Present

 

Inference

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

Test For Phosphate

Experiment

Small  samples  of  each  brand  of cold  drinks  were  taken  in separate  test  tubes  and  Ammonium  Molybdate  followed  by concentrated Nitric Acid (HNO₃) was added  to  it. The solution was heated. Appearance of canary-yellow precipitate confirmed the presence of phosphate ions in cold drinks.

Observation

Sr. No.	Name Of The Drink	Observation	Conclusion
1.	Coca Cola	Canary Yellow Precipitate	Phosphate is Present
2.	Sprite	Canary Yellow Precipitate	Phosphate is Present
3.	Limca	Canary Yellow Precipitate	Phosphate is Present
4.	Fanta	Canary Yellow Precipitate	Phosphate is Present

 

Inference

All the soft drinks samples gave positive test for phosphate ions. Hence all the cold drinks contain phosphate.

Test For Alcohol

Experiment

Small  samples  of  each  brand  of  cold  drinks  were  taken  in separate test tubes  and  Iodine  followed by  Potassium  Iodide and Sodium Hydroxide (NaOH) solution was added to each test tube. Then the test tubes were heated in hot water bath for 30 minutes. Appearance of yellow coloured precipitate confirmed the presence of alcohol in cold drinks.

Observation

Sr. No.	Name Of The Drink	Observation	Conclusion
1.	Coca Cola	Yellow Precipitate	Alcohol is Present
2.	Sprite	Yellow Precipitate	Alcohol is Present
3.	Limca	Yellow Precipitate	Alcohol is Present
4.	Fanta	Yellow Precipitate	Alcohol is Present

Inference

All the cold drinks samples gave positive test for alcohol. Hence all the cold drinks contain alcohol.

Chemical Reaction

CH₃CH₂OH + 4I₂ + 6NaOH → CHI₃ + HCOONa + 5NaI + 5H₂O

Test for Sucrose

Experiment

5 ml samples of each brand of cold drinks  were  taken  in separate china dishes and were heated very strongly until changes occur. Black coloured residue left confirmed the presence of sucrose in cold drinks.

Observation

Sr. No.	Name Of The Drink	Observation	Conclusion
1.	Coca Cola	Black Residue	Sucrose is Present
2.	Sprite	Black Precipitate	Sucrose is Present
3.	Limca	Black Precipitate	Sucrose is Present
4.	Fanta	Black Precipitate	Sucrose is Present

 

Inference

All the brands of cold drinks contain sucrose. But amount of sucrose varies in each brand of drink. Fanta contains 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 and carbon dioxide. All cold drinks are acidic in nature. On comparing the pH value of different brands Coca Cola is the most acidic and Limca is least acidic of all the four brands taken.

Among the four samples of cold drinks taken, Sprite has the maximum amount of dissolved carbon dioxide and Fanta has the minimum amount of dissolved carbon dioxide.

Precautions

1. Some of the precautions which need to be taken care of are
2. Concentrated solutions should be handled with immense care.
3. Hands should be washed thoroughly after performing each experiment.
4. If possible, one should wear hand gloves to prevent from any possible damage.
5. If chemicals come into contact with your skin or eyes, flush immediately with copious amounts of water.
6. Never leave burners unattended. Turn them off whenever you leave your workstation.
7. Never point a test tube or any vessel that you are heating at yourself or your neighbo

Conclusion

DIS-ADVANTAGES OF COLD DRINKS

1. Soft drinks are little more harmful than sugar solution. As they contain sugar in large amount which cause problems in diabetes patients.
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 humpers.
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 loose a rusted bolt.

Chemistry project on Preparation of Potash Alum