A) \[6\times {{10}^{-21}}\]
B) \[5\times {{10}^{-19}}\]
C) \[5\times {{10}^{-8}}\]
D) \[3\times {{10}^{-20}}\]
Correct Answer: D
Solution :
\[\text{HCl(aq)}\xrightarrow{{}}\underset{\text{0}\text{.2M}}{\mathop{{{\text{H}}^{\text{+}}}\text{(aq)+}}}\,\text{C}{{\text{l}}^{\text{-}}}\text{(aq)}\] \[{{\text{H}}_{2}}S(aq){{H}^{+}}(aq)+H{{S}^{-}}(aq),{{k}_{1}}=1\times {{10}^{-7}}\] \[\text{H}{{S}^{-}}(aq){{H}^{+}}(aq)+{{S}^{-2}}(aq),{{k}_{2}}=1.2\times {{10}^{-13}}\] \[{{\text{H}}_{2}}{{S}^{-}}(aq)2{{H}^{+}}(aq)+{{S}^{-2}}(aq),{{K}_{eq}}={{k}_{1}}\times {{k}_{2}}\] \[\text{0}\text{.1M}\] \[{{\text{K}}_{eq.}}=1.2\times {{10}^{-20}}=\frac{{{[0.2]}^{2}}[{{S}^{-2}}]}{0.1}\] \[\text{ }\!\![\!\!\text{ }{{\text{S}}^{\text{-2}}}\text{ }\!\!]\!\!\text{ =3 }\!\!\times\!\!\text{ 1}{{\text{0}}^{\text{-20}}}\text{M}\]You need to login to perform this action.
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