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Class 12 chemistry investigatory project on the analysis of cold drinks

Text of Chemistry Investigatory project

CHEMISTRY PROJECTAnalysis of Commonly Available Cold Drinks

Project by:


This is hereby to certify that the original and genuine investigation work has been carried out to investigate about the subject matter and the related data collection and investigation has been completed solely, sincerely and satisfactorily by, regarding his project titled ANAYLSIS OF COMMONLY AVAILABLE COLD DRINKS.

Teachers Signature


It would be my utmost pleasure to express my sincere thanks to my in providing a helping hand in this project. His valuable guidance, support and supervision all through this project are responsible for attaining its present form. I would also like to thank my parents as they encouraged me to put forward my project.


I. Introduction II. TheoryIII. AimIV. Apparatus V. Chemical RequiredVI. Determination of pHVII. Test for Carbon dioxideVIII. Test for Glucose IX. Test for PhosphateX. Test for AlcoholXI. Test for SucroseXII. ResultXIII. ConclusionXIV. PrecautionBibliography


A cold drink is abeveragethat typically containscarbonated water, asweetenerand aflavoring. The sweetener maybe sugar,high-fructose corn syrup, fruit juice,sugar substitutesor some combination of these. Soft drinks may also containcaffeine, colorings, preservatives and other ingredients.Cold drinks have been around in the country since the 1950s. Parle Group is regarded as the first Indian company to circulate soft drinks nationwide. Gold Spot, a proprietary drink, faced no competition until the all empowering Coca Cola entered the country. Gold Spot was complimented with two other soft drinks, Thumbs Up and Limca. Today, a large population is witnessed, in-taking these carbonated drinks Coca Cola and Pepsi for their revitalizing attributes; Limca, Fanta, Sprite for giving a feeling of lightness.

TheoryCold 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. 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. 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




Test Tubes Test Tube Holder Test Tube Stand Stop Watch Beaker Bunsen Burner pH Paper Tripod Stand China Dish Wire Gauge Water Bath

Chemicals Required

Iodine Solution Potassium Iodide Sodium Hydroxide Lime Water Fehlings A & B Solution Concentrated Nitric Acid Benedict Solution Ammonium Molybdate

Determination of pH

ExperimentSmall 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.ObservationSr.n.Name of the drinkColour changepH

1.Coca ColaPinkish2-3

2.LimcaLight Orange4

3.SpriteDark Orange3

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

ObservationSr.n.Name of the drinkTime taken(sec)Inference

1.Coca Cola28CO2 Present

2.Limca28CO2 Present

3.Sprite20CO2 Present

All cold drinks contain CO2 dissolved in water, which is what adds the tangy flavor to the drinks.Chemical Reaction Ca(OH)2 + CO2 CaCo3 + H2O

Test for GlucoseExperimentGlucose is a reducing sugar. Its presence can be tested through the following methods :1. Benedicts Reagent TestSmall sample of the cold drink of different brand is taken in a test tube and a few drops of Benedicts reagent are added. The test tube is heated for a few seconds. Reddish ppt. confirms the presence of glucose.


Sr.n.Name of the drinkObservationInference

1.Coca Cola Reddish ppt.Glucose is present

2.LimcaReddish ppt.Glucose is present

3.SpriteReddish ppt.Glucose is present

All samples consist of glucose, as all of them give a positive result for Benedicts test.

2. Fehlings Solution TestSmall samples of cold drinks of different brands were taken in a test tube and a few drops of Fehlings A solution and Fehlings 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.

Sr.n.Name of the drinkObservationInference

1.Coca ColaReddish Brown ppt.Glucose is present

2.Limca Reddish Brown ppt.Glucose is present

3.SpriteReddish Brown ppt.Glucose is present

All samples gave positive test for glucose with Fehlings (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


Sr.n.Name of the drinkObservationInference

1.Coca ColaCanary-Yellow ppt.Phosphate present

2.LimcaCanary-Yellow ppt.Phosphate present

3.SpriteCanary-Yellow ppt.Phosphate present

All the cold drink samples contain Phosphate.

Chemical reactionNaHPO4 + 12 (NH4)2MoO4 + 21 HNO3 + 3H (NH4)3PO4.12Moo3+ 21HN4NO3 + 12H2O

Test For Alcohol

ExperimentSmall 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 colored precipitate confirmed the presence of alcohol in cold drinks


Sr.n.Name of the drinkObservationInference

1.Coca ColaYellow ppt.Alcohol Present

2.LimcaYellow ppt.Alcohol Present

3.SpriteYellow ppt.Alcohol Present

All the samples consist of Alcohol.

Chemical ReactionCH3CH2OH + 4I2 + 6NaOH CHI3 + HCOONa + 5 NaI + 5H2O

Test For Sucrose


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


Sr.n.Name of the drinkObservationInference

1.Coca ColaBlack ResidueSucrose is present

2.LimcaBlack ResidueSucrose is present

3.SpriteBlack ResidueSucrose is present

All brands of cold drinks contain sucrose.


After conduction of several tests, we find that all the different brands namely -

1. Coca Cola2. Limca3. Sprite

- contain glucose, sucrose, alcohol, phosphate, and carbon dioxide. All are acidic in nature. Coca Cola comes out to be the most acidic of the three and Limca, the least.

Carbon Dioxide content is maximum in Sprite and minimum in Coca Cola.


Intake of soft drinks, as many studies have conclusively shown, interferes with our neurological and physiological state of being owing to their contents.All the brands tested, contain high quantity of sugar which is more than what our body demands on an average day.The strength of phosphoric acid, as depicted above, is enough to dissolve nails in 4 days.

Recommendation :Out of the three brands, Limca contains the least amount of dissolved CO2 and is the least acidic. Relatively, it has a lower sugar content than the other three. Taking these facts into account, we can conclude that Limca is the safest of the three.


Some of the precautions which need to be taken care of are

Concentrated solutions should be handled with immense care. Hands should be washed thoroughly after performing each experiment. If possible, one should wear hand gloves to prevent from any possible damage. If chemicals come into contact with your skin or eyes, flush immediately with copious amounts of water. Never leave burners unattended. Turn them off whenever you leave your workstation.


The following books were a source for my project

NCERT Chemistry Textbook for Class XII Dr. N. K. Verma, Chemistry Lab Ma

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