Identifying ions

Question 1

CO3 2- test

Answer 1

Add any acid to produce effervescence, by reaction with H+(aq) forming CO2(g).

Question 2

SO4 2- test

Answer 2

Add HCl to remove impurities (or any acid not sulphuric acid) then barium chloride solution to produce a white ppt, by precipitation with Ba2+(aq).

Question 3

Cl - test

Answer 3

Add nitric acid then silver nitrate solution, then test solubility in aqueous ammonia to produce a white ppt that dissolves in dilute ammonia.

Question 4

Br - test

Answer 4

Add nitric acid then silver nitrate solution, then test solubility in aqueous ammonia to produce a cream ppt that dissolves in concentrated ammonia.

Question 5

I - test

Answer 5

Add nitric acid then silver nitrate solution, then test solubility in aqueous ammonia to produce a yellow ppt that does not dissolve in ammonia.

Question 6

NH4 + test

Answer 6

Warm with sodium hydroxide solution and test for ammonia gas with damp litmus to turn damp litmus blue.

Question 7

Cu 2+ test

Answer 7

Add sodium hydroxide solution to produce a blue ppt.

Question 8

Fe 2+ test

Answer 8

Add sodium hydroxide solution to produce a dark green ppt.

Question 9

Fe 3+ test

Answer 9

Add sodium hydroxide solution to produce a red brown ppt.

Question 10

Mn 2+ test

Answer 10

Add sodium hydroxide solution to produce a light brown ppt.