Question

$A{g}^{+}+N{H}_3\rightleftharpoons \left[Ag\right(N{H}_3){]}^{+};K_1=2000$
$\left[Ag\right(N{H}_3){]}^{+}+N{H}_3\rightleftharpoons [Ag(N{H}_3{)}_2{]}^{+};K_2=8000$
then the formation constant of $\left[Ag\right(N{H}_3{)}_2{]}^{+}$ is:

• A. $1.6\times {10}^7$
• B. ${10}^5$
• C. $4$
• D. $6\times {10}^3$

Answer 1

The correct option is A $1.6\times {10}^7$

$A{g}^{+}+N{H}_3\rightleftharpoons \left[Ag\right(N{H}_3){]}^{+};K_1=2000$
$Ag\left(N{H}_3\right){]}^{+}+N{H}_3\rightleftharpoons \left[Ag\right(N{H}_3{)}_2{]}^{+};K_2=8000$
Adding : $A{g}^{+}+2N{H}_3\rightleftharpoons \left[Ag\right(N{H}_3{)}_2{]}^{+};K$
$\therefore K=K_1\times K_2=1.6\times {10}^7$