Question

The hydrolysis of an ester was carried out separately with $0.05$ $N$ $HCl$ and $0.05$ $N$ $H_{2}S{O}_4$. Which of the following will be true?

• A. $k_{HCl}>k_{H_{2}S{O}_4}$
• B. $k_{H_{2}S{O}_4}>k_{HCl}$
• C. $k_{H_{2}S{O}_4}=2k_{HCl}$
• D. $k_{H_{2}S{O}_4}=k_{HCl}$

Answer 1

The correct option is A $k_{HCl}>k_{H_{2}S{O}_4}$

Number of dissociation protons in $HCl$ is 1 per molecule. So we have $0.5N\left[H^{+}\right]$ for $0.5NHCL$ in $H_2{SO}_4$ this is 1 per molecule so for $0.5N\left[H_2{SO}_4\right]$ we have $0.25N\left[H^{+}\right]$.

Thus, $v_{HCL}>v_{H_2{So}_4}\Rightarrow k_{HCl}>k_{H_2{SO}_4}$