Test for Cations

Question 1

Aluminium + Sodium Hydroxide

Answer 1

White precipitate, soluble in excess, giving a colorless solution

Question 2

Aluminium + Ammonia

Answer 2

White Precipitate, insoluble in excess

Question 3

Ammonium + Sodium Hydroxide

Answer 3

Ammonia Gas produced on warming, turning damp red litmus paper blue

Question 4

Calcium + Sodium Hydroxide

Answer 4

White Precipitate insoluble in excess

Question 5

Calcium + Ammonia

Answer 5

No/Very slight white precipitate

Question 6

Chromium(III) + Sodium Hydroxide

Answer 6

Green precipitate, soluble in excess

Question 7

Chromium(III) + Ammonia

Answer 7

Green precipitate, insoluble in excess

Question 8

Copper(II) + Sodium Hydroxide

Answer 8

Light blue precipitate, insoluble in excess

Question 9

Copper(II) + Ammonia

Answer 9

Light blue precipitate soluble in excess, giiving a dark blue solution

Question 10

Iron(II) + Sodium Hydroxide

Answer 10

Green precipitate, insoluble in excess, turns brown near surface

Question 11

Iron(II) + Ammonia

Answer 11

Green precipitate, insoluble in excess, turns brown near surface

Question 12

Iron(III) + Sodium Hydroxide

Answer 12

Red-Brown precipitate, insoluble in excess

Question 13

Iron(III) + Ammonia

Answer 13

Red-Brown precipitate insoluble in excess

Question 14

Zinc + Sodium Hydroxide

Answer 14

White precipitate soluble in excess, giving a colorless solution

Question 15

Zinc + Ammonia

Answer 15

White precipitate, soluble in excess, giving a colorless solution