Kc for the the reaction, [ Ag ( CN )2]- leftharpoons Ag ++2 CN -, the equillibrium constant at 25° C is 4.0 × 10-19, then the silver ion concentration in a solution which was originally 0.1 molar in KCN and 0.03 molar in AgNO 3 is :

Question

Kc for the the reaction, [ Ag ( CN )2]- leftharpoons Ag ++2 CN -, the equillibrium constant at 25° C is 4.0 × 10-19, then the silver ion concentration in a solution which was originally 0.1 molar in KCN and 0.03 molar in AgNO 3 is : (A) 7.5 × 1018 (B) 7.5 × 10-19 (C) 7.5 × 1019 (D) 7.5 × 10-18

Tardigrade Admin · Accepted Answer

0.04 ≈ 0.04 ∴ Kc = 4 × 10-19 = ((0.04)2 × a/0.03) a = 7.5 × 10-18

Q. $K_{c}$ for the the reaction, $[A g (CN)_{2}]^{-} ⇌ A g^{+} + 2 C N^{-}$ , the equillibrium constant at $2 5^{\circ} C$ is $4.0 \times 1 0^{- 19}$ , then the silver ion concentration in a solution which was originally $0.1$ molar in $K CN$ and $0.03$ molar in $A g N O_{3}$ is :

$7.5 \times 1 0^{18}$

$7.5 \times 1 0^{- 19}$

$7.5 \times 1 0^{19}$

$7.5 \times 1 0^{- 18}$

$0.04 \approx 0.04$
$∴ K_{c} = 4 \times 1 0^{- 19} = \frac{( 0.04 ) ^{2} \times a}{0.03}$
$a = 7.5 \times 1 0^{- 18}$

Q. Kc​ for the the reaction, [Ag(CN)2​]−⇌Ag++2CN−, the equillibrium constant at 25∘C is 4.0×10−19, then the silver ion concentration in a solution which was originally 0.1 molar in KCN and 0.03 molar in AgNO3​ is :

7.5×1018

7.5×10−19

7.5×1019

7.5×10−18