Determination of contents of cold
drinks
Muhammad Hassan Sohail
Grade: 10 B3
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. Cold drinks
detected by the PH paper are bit acidic in nature. The
pH values also depend upon the acidic contents such as
citric acid and phosphoric acid. Carbondioxide present in
cold drinks can be estimated by presence of effervescence
on shaking the bottle. Actually Carbondioxide is filled in
bottle under pressure and is present in the drink as
bicarbonates which is a weak acid. That’s why drinks
are sour in taste.
Apparatus used
i.
ii.
iii.
iv.
v.
Test Tube
Test Tube Holder
Test Tube Stand
Stop Watch
Beaker
vi.
vii.
viii.
ix.
x.
xi.
Burner
pH Paper
Tripod Stand
China Dish
Wire Gauge
Water Bath
Chemicals needed
i.
ii.
iii.
iv.
v.
vi.
vii.
viii.
Iodine Solution
Potassium Iodine
Sodium Hydroxide
Fehling’s A & B Solution
Lime Water
Concentrated HNO3
Benedict Solution
Ammonium Molybdate
Test for PH
Procedure:
Small samples of cold drinks of different brands were
taken in a test tube and blue litmus paper was put inside
each test tube.
Observation
Number
1
2
3
4
Name of the drink
Coca-cola
Sprite
Lemonade
Fanta
Change
Blue litmus paper turns red
Blue litmus paper turns red
Blue litmus paper turns red
Blue litmus paper turns red
Test for carbon dioxide
Procedure:
Bottles of fizzy drinks were opened and put in a test
tube. Then limewater was put in the test tube and the
product was observed.
Observation
Number
1
2
3
4
Name of the drink
Coca-cola
Sprite
Lemonade
Fanta
Time taken
26.5s
21s
35s
36s
Product formed
Co2 is present
Co2 is present
Co2 is present
Co2 is present
Chemical reaction involved
Ca(OH)2(s) + CO2(g)
CaCO3(s) + H2O(s)
Test for glucose
Procedure:
Glucose is a reducing sugar acid. Its presence is detected
by the Benedict’s regent 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 colour confirmed the
presence of glucose in cold drinks.
Observation
Number
1
2
3
4
Name of the drink
Coca-cola
Sprite
Lemonade
Fanta
Product formed
Reddish colour precipitate
Reddish colour precipitate
Reddish colour precipitate
Reddish colour precipitate
Test for phosphate
Procedure:
Small samples of cold drinks were taken in separate test
tubes and Ammonium Molybdate with concentrated
Nitric was added to it. The solution was heated.
Appearance of yellow precipitate confirmed the presence
of phosphate in cold drinks.
Observation
Number
1
2
3
4
Name of the cold drink
Coca-cola
Sprite
Lemonade
Fanta
Product formed
Yellow precipitate
Yellow precipitate
Yellow precipitate
Yellow precipitate
Chemical reaction involved:
NaHPO4 + 12(NH4)2MoO4 + 21HNO3 + 3H+
(NH4)3PO4.12MoO3 +
21HN4NO3 + 12H2O
Test for alcohol
Procedure:
Small samples of cold drinks were taken in separate test
tubes and Iodine with 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
tells us that alcohol is present the presence of alcohol in
cold drinks.
Observation
Number
1
2
3
4
Name of the cold drink
Coca-cola
Sprite
Lemonade
Fanta
Product formed
Yellow precipitate
Yellow precipitate
Yellow precipitate
Yellow precipitate
Chemical reaction involved:
CH3CH2OH + 4I2 + 6NaOH
CHI3 + HCOONa + 5NaI + 5H2O
Conclusion
All cold drinks contain glucose, alcohol, phosphate and
carbon dioxide. All cold drinks are acidic in nature. By
looking at the tables, we see that Coca Cola is the most
acidic and Limca is least acidic in between Fanta and
Sprite. We also concluded that amoung the cold drinks
tested, Sprite has the maximum amount of CO2.