A metal which is not affected by conc. H2 SO4 , HNO3 or alkalis forms a compound X. This compound X can be used to give a complex which finds its application for toning in photography? The metal is
(a) Au
(b) Ag
(c) Hg
(d) Cu
Correct option: (a) Au
Explanation:
Au, the gold is not attacked by acids and alkalis. It forms AuCl3 .AuCl3 further reacts with HCl to form H[Au(Cl)4 ] which is used in photography.
