Diffusion 4.02
Experiment 4. Discussion
I What colour change is usually seen when iodine solution is added to starch, or starch
to iodine ?
2 After 10-15 minutes, what colour was (a) the starch solution in the cellophane tubing
and (b) the iodine solution in the test-tube ?
3 How can you explain the fact that the same colour change had not occurred in both
solutions ? (There are two possible explanations.)
4 What result would you expect if the iodine solution was in the cellophane tubing and
the starch solution in the test-tube ?
5 What properties must the cellophane tubing possess if these results are to be
explained ?