Question

What are the units in which the solubility product of `Ca_(3)(PO_(4))_(2)` is expressed?
A. `mol dm^(-3)`
B. `mol^(2) dm^(-6)`
C. `mol^(3) dm^(-9)`
D. `mol^(5) dm^(-15)`

Answer 1

Correct Answer - D
`{:(Ca_(3)(PO_(4))_(2)hArr,3Ca^(2+)+,2PO_(4)^(3-)),(,3x,2x):}`
`K_(sp) = (3x)^(2) (2x)^(2) = 108 x^(5)`
`:.` Units of `K_(sp)` is `("concentration")^(5) = ("mol dm"^(-3))^(5) = "mol"^(5) "dm"^(-15) = "mol"^(5) "dm"^(-15)`