Aq Cations (NaOH)

Question 1

Aluminium (Al3+)

Answer 1

•White ppt
•Soluble in excess= colourless solution

Question 2

Ammonium (NH4+)

Answer 2

•Produces Ammonia (NH3) on warming
•No visible change = use red litmus paper

Question 3

Calcium (Ca2+)

Answer 3

•White ppt
•Insoluble in excess

Question 4

Chromium (Cr3+)

Answer 4

•Green ppt
•Soluble in excess

Question 5

Copper (Cu2+)

Answer 5

•Light Blue Ppt
•Insoluble in excess

Question 6

Iron (Fe2+)

Answer 6

•Green Ppt
•Insoluble in excess

Question 7

Iron (Fe3+)

Answer 7

•Red-brown ppt
•Insoluble in excess

Question 8

Zinc (Zn2+)

Answer 8

•White ppt
•Soluble in Excess = colourless solution

Question 9

PATTERNS

Answer 9

-all transition metals (except Zinc and Chromium) are insoluble in excess
-Aluminium and Zinc in excess are colourless solutions
-Zinc, Calcium and Aluminium ALL give white ppt
-Chromium and Iron(2+) both give green ppt