Other tests

Question 1

What are the tests for

The presence of water

Answer 1

The copper sulfate test and the cobalt chloride test

Question 2

What is

The copper sulfate test

Answer 2

Water will turn anhydrous copper(II) sulfate into hydrated copper(II) sulfate. The colour will change from white to blue.

Question 3

What is

The cobalt chloride test

Answer 3

Water will turn anhydrous anhydrous cobalt(II) chloride into hydrated cobalt(II) chloride. The colour will change from blue to pink.

Cobalt chloride paper is blue and turns pink with water.

Question 4

What’s the test for

The purity of water

Answer 4

Testing that the boiling point is exactly 100°C

Question 5

What’s the test and result for

Unsaturated hydrocarbons (alkenes)

Answer 5

Test: Add it to a solution of bromine in water and shake

Result: Alkenes decolorise the bromine water, resulting in a clear, colourless liquid

Alkanes have no reaction to this test.