Tests for ions

Question 1

Flame test for lithium ions

Answer 1

Crimson

Question 2

Flame test for sodium ions

Answer 2

Yellow

Question 3

Flame test for potassium ions

Answer 3

Lilac

Question 4

Flame test for calcium ions

Answer 4

Brick Red

Question 5

Flame test for barium ions

Answer 5

Green

Question 6

Flame test for copper(II) ions

Answer 6

Blue

Question 7

Test for silver ions

Answer 7

Add sodium hydroxide, brown precipitate formed (silver oxide)

Question 8

Test for calcium ions

Answer 8

Add sodium hydroxide, white precipitate

Question 9

Test for copper(II) ions

Answer 9

Add sodium hydroxide, blue precipitate

Question 10

Test for lead(II) ions

Answer 10

Add sodium hydroxide, white precipitate

Question 11

Test for iron(II) ions

Answer 11

Add sodium hydroxide, green precipitate

Question 12

Test for zinc ions

Answer 12

Add sodium hydroxide, white precipitate, redissolves in excess NaOH to give colourless solution

Question 13

Test for aluminium ions

Answer 13

Add sodium hydroxide, white precipitate, redissolves in excess NaOH to give colourless solution

Question 14

Test for carbonates

Answer 14

Add HCl, carbon dioxide released turns limewater cloudy

Question 15

Test for sulfates

Answer 15

Add HCl to remove impurities, add barium chloride solution, white precipitate formed

Question 16

Test for ammonium ions

Answer 16

Warm gently with sodium hydroxide, ammonia released turns damp red litmus paper blue

Question 17

Test for hydroxides

Answer 17

Turns red litmus paper blue

Question 18

Test for halides (chlorides, bromides, iodides)

Answer 18

Add nitric acid (HNO3) and silver nitrate (AgNO3) solution.
Chloride - white precipitate
Bromide - cream precipitate
Iodide - yellow precipitate

Question 19

Test for nitrates

Answer 19

Warm gently with sodium hydroxide and Devarda’s Alloy

Ammonia released turns damp red litmus paper blue