Question

If solubility product of Zr₃(PO₄)₄ is denoted by K_sp and its molar solubility is denoted by S, then which of the following relation between S and K_sp is correct?

Options

• S = `(("K"_"sp")/144)^(1/6)`

• S = `(("K"_"sp")/6912)^(1/7)`

• S = `(("K"_"sp")/929)^(1/9)`

• S = `(("K"_"sp")/216)^(1/7)`

Answer 1

S = `(("K"_"sp")/6912)^(1/7)`

Explanation:

For \[\ce{Zr3\underset{SM}{(PO4)4} <=> \underset{3SM}{3Zr^{4+}} + \underset{4 SM}{4PO^{3-}_4}}\]

`therefore "K"_"sp" = ["Zr"^(4+)]^3 ["PO"_4^(3-)]^4`

`=> "K"_"sp" = (3 "S")^3 xx (4 "S")^4`

`=> "K"_"sp" = 27 xx 256 xx "S"^7`

`=> "S" = (("K"_"sp")/6912)^(1/7)`

This is the relation between molar solubility and solubility product.