Chemistry 5070 · O Level · Identification of ions and gases
Identification of ions and gases — practice question
The following aqueous solutions of four different metal sulfates are supplied:
• chromium(III) sulfate
• copper(II) sulfate
• iron(II) sulfate
• iron(III) sulfate
(a)[3]
With reagents available in a laboratory, suggest a test that confirms the sulfate ion in each of the four solutions. State the test and the observation.
(b(i))[4]
Use the observations with aqueous sodium hydroxide to deduce the cation in each solution and complete the table.
(b(ii))[4]
Write in the table the observations that indicate each cation when aqueous ammonia is added.
Worked solution & mark scheme
This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Aqueous barium nitrate / aqueous Ba(NO3)2 / aqueous barium chloride / aqueous BaCl2” …