Question

A solution of `MgCl_(2)` in water has pH
A. `lt7`
B. `gt7`
C. 7
D. 14.2

Answer 1

Correct Answer - A
`MgCl_(2)` is a salt of weak base `[Mg(OH)_(2)]` and strong acid (HCl). Therefore, it undergoes cationic hydrolysis to give an acidic solution having `pHlt7`.
`Mg^(2+)+2H-OHrarrMh(OH)_(2)+2H^(+)`
Magnesium hydroxide is almost completely insoluble in water.