Answer
$(b) [Ag^+]^2[C{O_3}^{2-}]$ is the correct answer.
Work Step by Step
1. Write the solubility equation of $Ag_2CO_3$ , and balance it:
$Ag_2CO_3(s) \lt -- \gt Ag^+(aq) + C{O_3}^{2-}(aq)$
$1Ag_2CO_3(s) \lt -- \gt 2Ag^+(aq) + 1C{O_3}^{2-}(aq)$
2. Now, write the $K_sp$ expression:
- It will be the multiplication of the concentrations of the ions.
$K_{sp} = [Ag^+][C{O_3}^{2-}]$
- Remember: the balance coefficient will be the exponent of the concentration:
$K_{sp} = [Ag^+]^2[C{O_3}^{2-}]^1$
$K_{sp} = [Ag^+]^2[C{O_3}^{2-}]$
