The iodine test for starch

Question 1

To test for the presence of starch in a sample, add a few drops of ……………………. in potassium……….. solution to the sample

Answer 1

orange/brown iodine

iodide

Question 2

The iodine is in potassium iodide solution as iodine is……… in water

Answer 2

insoluble

Question 3

If starch is present, iodide ions in the solution interact with the centre of starch molecules, producing a complex with a distinctive ……… colour

Answer 3

blue-black

Question 4

This test is useful in experiments for showing that starch in a sample has been digested by enzymes