A pale yellow inorganic compound K is insoluble in hot and dil. HNO3 but dissolves in concentrated a — Qualitative and Quantitative Analysis Chemistry Question

Question

A pale yellow inorganic compound K is insoluble in hot and dil. HNO3 but dissolves in concentrated ammonia solution and compound L is formed. On treatment with dil. HNO3 compound L produces a metal cation which gives white precipitate M with Hypo solution. When an aqueous solution of (M) is boiled, a black precipitate of (N) is formed which dissolves in hot dil. HNO3 and on adding HCl gives a white precipitate. When the compound (K) is heated with concentrated H2SO4 and MnO2 brown fumes are observed.