Question

Select the correct statement(s) for double salt :

• A. Double salts are stable in solid state but loose their identity in aqueous solution.
• B. In double salt the properties of constituent ions are not changed in their aqueous solution.
• C. Double salts are stable in solid-state and do not lose their identity in aqueous solution.
• D. In double salt the properties of constituent ions are changed in their aqueous solution.

Answer 1

Answer: (A), (B)

The correct options are
A Double salts are stable in solid state but loose their identity in aqueous solution.
B In double salt the properties of constituent ions are not changed in their aqueous solution.

Double salts are addition compounds formed by the combination of two or more stable compounds in stoichiometric proportions. Carnallite is a double salt formed when KCl and $MgC{l}_2$ combine with 6 molecules of water.($KCl.MgC{l}_2.6H_{2}O$).
$K_{2}S{O}_4+A{l}_2(SO-4{)}_3+24H_{2}O$ forms potash Alum $K_{2}S{O}_4.A{l}_2(S{O}_4{)}_3.24H2O$. These are examples of double salts. In a dissolved state, these double salts lose their identity to form metal ions and non metal ions or radicals. CuSO4 combines in stoichiometric proportions with $N{H}_3$ and water and forms tetrammine copper(II) sulphate mono hydrate ($CuS{O}_4.4N{H}_3.H_{2}O$), which is a complex or coordinate compound.
Hence options A & B are correct.