qualitative analysis (cation tests)

Question 1

sodium hydroxide —> white ppt., soluble in excess —> colourless solution
ammonia (aq) —> white ppt., insoluble in excess
hydrochloric acid —> no ppt.

Answer 1

aluminium ions

Question 2

sodium hydroxide —> white ppt., soluble in excess —> colourless solution
ammonia (aq) —> white ppt., insoluble in excess
hydrochloric acid —> white ppt.

Answer 2

lead (II) ions

Question 3

sodium hydroxide —> warm —> ammonia produced

Answer 3

ammonium ions

Question 4

sodium hydroxide —> white ppt., insoluble in excess
ammonia (aq) —> no ppt.

Answer 4

calcium ions

Question 5

sodium hydroxide —> light blue ppt., insoluble in excess
ammonia (aq) —> light blue ppt., soluble in excess —> dark blue solution

Answer 5

copper (II) ions

Question 6

sodium hydroxide —> green ppt., insoluble in excess
ammonia (aq) —> green ppt., insoluble in excess

Answer 6

iron (II) ions

Question 7

sodium hydroxide —> reddish-brown ppt., insoluble in excess
ammonia (aq) —> reddish-brown ppt., insoluble in excess

Answer 7

iron (III) ions

Question 8

sodium hydroxide —> white ppt., soluble in excess —> colourless solution
ammonia (aq) —> white ppt., soluble in excess —> colourless solution

Answer 8

zinc ions