Question

$ Ag ^{+}+ NH _3 \rightleftharpoons\left[ Ag \left( NH _3\right)\right]^{+} ; k_1=6.8 \times 10^{-3} $
${\left[ Ag \left( NH _3\right)\right]^{+}+ NH _3 \rightleftharpoons\left[ Ag \left( NH _3\right)_2\right]^{+} ; k_2=1.6 \times 10^{-3}}$
then the formation constant of the complex $\left[ Ag \left( NH _3\right)_2\right]^{+}$is

• A. $1.08 \times 10^{-7}$
• B. $1.08 \times 10^{-5}$
• C. $1.08 \times 10^{-9}$
• D. none of thee

Answer 1

Answer: (B)

$K = k_{1} × k_{2}$
$= \left(6.8 \times 10^{-3}\right)\times \left(1.6 \times 10^{-3}\right) = 1.08 \times 10^{-5}$