\(K_{sp} = S \times (2S)^2\,\, K_{sp} = 4S^3\)
\(K_{sp} = 4 \times (2 \times 10^{-2})^3 \)
\(K_{sp} = 4 \times 8 \times 10^{-6} \,\,K_{sp} = 3.2 \times 10^{-6}\)