Ask Me Help Desk - How to find the Qsp

Write your equations...

$K_2CO_3 + CaCl_2 \rightarrow CaCO_3 + 2KCl$

$CaCO_3 \rightleftharpoons Ca^{2+} + CO_3 \ ^{2-}$

The Ksp of CaCO3 is given by:

$K_{sp} = \frac{[Ca^{2+}][CO_3\ ^{2+}]}{[CaCO_3]} = 8.7 \times 10^{-9}$

The Qsp of CaCO3 is given by:

$Q_{sp} = [Ca^{2+}][CO_3\ ^{2+}]$

To get your answer, find the number of moles of CaCO3 formed from the given data and the equation for the reaction.

Use the Ksp expression to find the number of moles of Ca^2+ and CO3 ^2-. Once you get those, you can find the Qsp.

Do you still have problems? If so, post back.