Cations

Question 1

Aluminium in NaOH

Answer 1

White ppt soluble in excess (Al(OH)4)-

Question 2

Ammonium (NH4+) in NaOH

Answer 2

Ammonia produced upon heating (describe test)

Question 3

Barium (Ba+) in NaOH

Answer 3

No ppt

Question 4

Calcium (Ca2+) in NaOH

Answer 4

White ppt insoluble in excess

Question 5

Chromium (Cr3+) in NaOH

Answer 5

Grey green ppt soluble in excess to give dark green solution

Question 6

Copper (cu2+) in NaOH

Answer 6

Pale blue ppt insoluble in excess

Question 7

Iron (II) (Fe2+) in NaOH

Answer 7

Green ppt Fe(OH)2 turns brown upon contact with air; insoluble in excess

Question 8

Iron (III) (Fe3+) in NaOH

Answer 8

red brown ppt insoluble in excess

Question 9

Magnesium (Mg2+) in NaOH

Answer 9

White ppt insoluble in excess

Question 10

Manganese (Mn2+) in NaOH

Answer 10

Off white ppt that rapidly turns brown upon contact with air; insoluble in excess

Question 11

Zinc (Zn2+) in NaOH

Answer 11

White ppt soluble in excess to give colourless solution of (Zn(OH)4)2-

Question 12

Al3+ in aq NH3

Answer 12

White ppt insoluble in excess

Question 13

BA 2+ in aq NH3

Answer 13

No ppt

Question 14

Ca2+ in aq NH3

Answer 14

No Ppt

Question 15

Cr3+ in aq NH3

Answer 15

Grey green ppt insoluble in excess

Question 16

Iron (II) Fe2+ in aq NH3

Answer 16

Green ppt turns brown upon contact with air

Insoluble in excess

Question 17

Copper (Cu2+) in aq NH3

Answer 17

Pale blue ppt

Soluble in excess to give dark blue solution

Question 18

Iron (III) Fe3+ in aq NH3

Answer 18

Red brown ppt

Insoluble in excess

Question 19

Mg2+ in aq NH3

Answer 19

white ppt insoluble in excess

Question 20

Mn2+ in aq NH3

Answer 20

Off white ppt that rapidly turns brown on contact with air

Insoluble in excess

Question 21

Zn2+ in aq NH3

Answer 21

White ppt

Soluble in excess