Question

Write the ksp expression for the sparingly soluble compound zinc phosphate, zn3(po4)2.

Answer 1

The give compound is a sparingly soluble salt,
`Zn_(3)(PO_(4))_(2)`. The solubility equilibrium for this compound can be represented as:

`Zn_(3)(PO_(4))_(2)(aq)<==>3Zn^(2+)(aq)+2PO_(4)^(3-)(aq)`

Initial(M) - 0 0

Change(M) - +3x +2x

Equilibrium(M) - 3x 2x

Solubility product expression for this equilibrium will be:

`K_(sp)=[Zn^(2+)]^(3)[PO_(4)^(3-)]^(2)`

=
`(3x)^(3)(2x)^(2)=108x^(5)`

Where x will be the molar solubility of the compound
`Zn_(3)(PO_(4))_(2)`at that given temperature.