Chapter 25: Tests for Gases, Anions and Cations

carbon dioxide

The test for ________ involves bubbling the gas through an aqueous solution of calcium hydroxide (limewater)

precipitate

If a(n) ________ is formed from NaOH then the hydroxide is insoluble in water.

Chlorine

________ should always be handled in a fume cupboard due to its toxicity.

Metal cations

________ in aqueous solution can be identified by the colour of the precipitate they form on addition of sodium hydroxide and ammonia.

carbon dioxide

If the gas is ________, the limewater turns milky or cloudy.

Lithium ions burn

crimson flame

Sodium ions burn

yellow flame

Potassium ions burn

lilac flame

Calcium ions burn

orange-red flame

Chlorine method

Use litmus paper

Carbon dioxide method

Bubble with an aqueous solution

Oxygen method

Glowing splint

Hydrogen method

lit splint

Copper ions burn

green flame

Test for anions

______often give precipitates