Question

Give a test that can be used to differentiate between butter and cooking oil.

Answer 1

If a carbon compound decolourises bromine water, it will be an unsaturated compound. Thus, we can distinguish between a cooking oil and butter by the bromine water test.
(i) Cooking oil decolourises bromine water. This shows that it is an unsaturated compound.
(ii) Butter does not decolourise bromine water. This shows that it is a saturated compound.