Chemical Tests

Question 1

Flame test color: Li +

Answer 1

Red

Question 2

Flame test color: Na +

Answer 2

Yellow

Question 3

Flame test color: K +

Answer 3

Lilac

Question 4

Flame test color: Ca 2+

Answer 4

Orange-red

Question 5

Flame test color: Cu 2+

Answer 5

Blue-green

Question 6

How to test for: NH4 +

Answer 6

Sodium hydroxide solution
Identify gas evolved using litmus paper
red -> blue

Question 7

How to test for: Cu 2+

Answer 7

Sodium hydroxide solution
Blue precipitate

Question 8

How to test for: Fe 2+

Answer 8

Sodium hydroxide solution
Green precipitate that slowly turns brown

Question 9

How to test for: Fe 3+

Answer 9

Sodium hydroxide solution
Red-brown precipitate

Question 10

Physical test to show water is pure

Answer 10

Boiling point test.
By heating water and measuring its boiling point
Pure water boils at 100°C at standard pressure.

Question 11

Cl–, Br– and I– using acidified silver nitrate solution
* SO42– using acidified barium chloride solution
* CO32– using hydrochloric acid and identifying the gas evolved.