Q. The solubility of $Ca_{3}\left( PO_{4} \right)_{2}$ in water is $y$ moles/litre. Its solubility product is
A) $6\ y^{4}$
B) $36\ y^{4}$
C) $64\ y^{5}$
D) $108\ y^{5}$
Explanation
(d)
$Ca_{3}\left( PO_{4} \right)_{2}(s) \rightleftharpoons 3{Ca}^{2 +}(aq) + 2{PO}_{4}^{3 -}(aq)$
$3y$ $2y$
$K_{sp} = \left\lbrack {Ca}^{2 +} \right\rbrack^{3}.\left\lbrack {PO}_{4}^{3 -} \right\rbrack^{2}$
$= (3y)^{3}.(2y)^{2}$
$= 27y^{3} \times 4y^{2}$
$= 108y^{5}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.