7 D is a green crystalline solid which dissolves in water to give a
very pale green solution. Addition of sodium hydroxide
solution to a solution of D produces a green precipitate, E,
which turns orange around the top on standing in air.
Addition of dilute hydrochloric acid and barium chloride
solution to a solution of D gives a white precipitate, F.
a) Identify D, E and F.
b) Write equations (full or ionic) for the reactions producing
E and F.