Class 6 Chemistry practical experiment: Iodine test for carbohydrates

Objective:
Test the presence of carbohydrates in common food items

Materials required:
Food items: Bread slice, Potato slice, Soaked chickpea seeds, 3% iodine solution, Dropper

Procedure:
• Place a bread slice, a potato slice and a few chickpea seeds (with seed coat removed) in separate and clean test tube
• With the help of a dropper, place 2-3 drops of iodine solution on each item
• Note the change in colour and record your observations

Findings:
Blue-black colour appears on bread slice and potato slice, whereas, chickpea seeds do not show any change in colour.

Conclusions:
Bread and potato contain starch which gives blue-black in colour on addition of iodine solution. Whereas, chickpea seeds do not contain starch and thus do not show any change in colour.
Starch is a type of carbohydrate present in many of our food items.
Carbohydrates are energy-yielding components of food