Question

if C is a soluble salt of copper what is the suitable method of its preparation

Answer 1

This method is used to prepare soluble salts. E.g. the addition of granulated zinc to a dilute solution of tetraoxosulphate (VI) acid - effervescence of hydrogen occurs.

Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g)

The solution is filtered, leaving insoluble impurities, such as excess zinc and particles of carbon on the filter paper. The ZnSO4 is then crystallized from the solution.