HCl was passed through a solution of `CaCl_2, MgCl_2 and NaCl` Which of the following compound(s) crystallise(s) ?

Options

A. Only NaCl
B. Only `MgCl_2`
C. NaCl, `MgCl_2` and `CaCl_2`
D. Both `MgCl_2` and `CaCl_2`

Answer

A

Explanation

When HCl is passed through the mixture of `CaCl_2, MgCl_2` and NaCl, `Cl^(-)` ion concentration increases, As `CaCl_2` and `MgCl_2` are more soluble than NaCl.
Hence ionic product `[Na^(+)] [Cl^(-)]` becomes more than solubility product. Thus, precipitation of NaCl occurs (due to common ion effect)