Select the correct statement about this reaction:
$$\begin{array} { l }
\mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { SH } + { } ^ { - } \mathrm { CN } \rightleftarrows \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm {~S} ^ { - } + \mathrm { HCN } \
\mathrm { p } K _ { \mathrm { a } } = 10.5 \
p K _ { \mathrm { a } } = 9.4 \
\end{array}$$

Question

Select the correct statement about this reaction:
$$\begin{array} { l } 
\mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { SH } + { } ^ { - } \mathrm { CN }  \rightleftarrows \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm {~S} ^ { - } + \mathrm { HCN } \
\mathrm { p } K _ { \mathrm { a } } = 10.5 \
p K _ { \mathrm { a } } = 9.4 \
\end{array}$$

Quizplus · Accepted Answer

The equilibrium constant (K) for the reaction can be calculated using the difference in pKa values of the acid (HCN, pKa = 9.4) and the thiol (CH3CH2SH, pKa = 10.5). The difference in pKa values is -1.1 (9.4 - 10.5), which means the equilibrium constant K = 10^(-1.1) ≈ 0.08, indicating the equilibrium lies to the left, favoring reactants.

Select the Correct Statement About This Reaction A) the Equilibrium Lies Very Far to the Right