Solid AgCl and solid AgSCN are in equilibrium with pure water. K_sp(AgCl) = 1.8 x 10^-10, K_sp(AgSCN) = 2.0 x 10^-12. Find [Ag+] in units of 10^-5 M (two decimals).

JEE Main levelNumerical answerDifficulty 2 of 3ia064

Solid $AgCl$ and solid $AgSCN$ are in equilibrium with pure water. $K_{s p} (AgCl) = 1.8 \times 1 0^{- 10}$ , $K_{s p} (AgSCN) = 2.0 \times 1 0^{- 12}$ . Find $[Ag X^{+}]$ in units of $1 0^{- 5} M$ (two decimals).

Numerical answer type, answer in x 10^-5 M, tolerance 0.01.

Charge balance:

[Ag X^{+}] = [Cl X^{-}] + [SCN X^{-}] = (K_{1} + K_{2}) / [Ag X^{+}]

. So

[Ag X^{+}] = 1.8 \times 1 0^{- 10} + 2.0 \times 1 0^{- 12} = 1.35 \times 1 0^{- 5} M = 1.35 \times 1 0^{- 5} M