Question

$A{g}^{+}N{H}_3\rightleftharpoons {\left[Ag\right(N{H}_3{)}^{+}]}^{+};K_1=6.8\times {10}^{-3}$
${\left[Ag\right(NH{)}_3]}^{+}+N{H}_3\rightleftharpoons {\left[Ag\right(N{H}_3{)}_2]}^{+};k_2=1.6\times {10}^{-3}$ then the formation constant of ${\left[Ag\right(N{H}_3{)}_2]}^{+}$ is:

• A. $6.8\times {10}^{-6}$
• B. $1.08\times {10}^{-5}$
• C. $1.08\times {10}^{-6}$
• D. $6.8\times {10}^{-5}$

Answer 1

Answer: (B)

$1.08\times {10}^{-5}$

Adding both the Reactions , we get

${Ag}^{+}N{H}_3+N{H}_3\to \left[Ag\right({N{H}_3}_2\left)\right]$

So , the formation constant becomes $K=K_1{K}_2$

Formation Constant = $1.08\times {10}^{-5}$