Question

What is the molarity of a saturated solution of $CaC{O}_3$? $(K_{sp}=2.8\times {10}^{-9})$

• A. $2.6\times {10}^{-5}$
• B. $2.8\times {10}^{-9}$
• C. $5.2\times {10}^{-5}$
• D. $5.6\times {10}^{-9}$

Answer 1

Answer: (C)

$5.2\times {10}^{-5}$

$K_{sp}=\left[C{a}^{2+}\right]\left[C{O}_3^{2-}\right]=x^2=28\times {10}^{-10}$

$x=5.29\times {10}^{-5}M$

$\therefore \left[CaC{O}_3\right]=5.29\times {10}^{-5}M$