(ai) Write the chemical formula for A, B, C and M.
(ii) Give the ionic equation, including the state symbols, for the formation of the dirty green precipitate.
(b) A colourless solution is suspected to contain either aluminium or lead(II) ions.
Describe a chemical test which can be used to identify the metal ions
present in the colourless solution and describe the expected observations.
(a)(i) A: H2SO4
(ii) Fe2+(aq) + 2OH–(aq) –> Fe(OH)2(s)
(b) Add hydrochloric acid/ sulfuric acid/ aq. potassium iodide. / any aqueous solution of chloride or sulfate. Hydrochloric acid/sulfuric acid: white ppt forms if lead(II) ion present; no visible reaction for aluminium ion. Aq. potassium iodide: yellow ppt forms if lead(II) ion present; no visible reaction for aluminium ion.