Question

The strength of an acid or base is related to its strength as an electrolyte. (a) Is the electrical conductivity of $\mathbf{\text{0.1MHCl}}$ electrical conductivity of $\mathbf{1}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{7}}$MHCl higher, lower, or the same as that of${\mathbf{\text{0.1MCH}}}_{\mathbf{\text{3}}}\mathbf{\text{COOH}}$? Explain.

(b) Is the electrical conductivity of$\mathbf{1}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{7}}$MHCl higher, lower, or the same as that of$\mathbf{1}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{7}}{\mathbf{\text{MCH}}}_{\mathbf{\text{3}}}\mathbf{\text{COOH}}$? Explain

Short answer

(a)${\text{0.1MHCl > 0.1MCHCHOOH}}_{\text{3}}.$

(b)$1\times {10}^{-7}\mathrm{MHCl}>1\times {10}^{-7}{\text{MCHHCOOH}}_{\text{3}}\text{COOH}$

Step-by-step solution

Step 1(a): To explain the electrical conductivity

The electrical conductivity of 0.1MHCl is higher than the electrical conductivity of ${\text{0.1MCHH}}_{\text{3}}\text{COOH}$. HCl is a strong acid and will dissociate fully unlike the weak acid${\text{CH}}_3\text{COOH.}$ With the equal amounts of initial concentration, the strong acid will produce more${\text{H}}_3{\text{O}}^{+}$ than its counterpart ion. In short, the strong acid will produce more ions than the weak acid. So, it will be a better conductor because it allows the transportation of charge in the solution.

Step 2(b): To explain the electrical conductivity

A $1\times {10}^{-7}$solution is a very diluted solution. Even if ${\text{the CH}}_{\text{3}}\text{COOH}$is a weak acid, its dissociation will increase as the solution becomes more diluted.Plus from the previous problems, one can observe that the auto ionization of the solvent will also contribute a significant amount of ions in the solution as the dilution increases. Therefore, the number of ions in both the solutions will be approximately the same, and the electrical conductivity of both the solutions will be approximately equal.

Hence, (a)${\text{0.1MHCl > 0.1MCHCHOOH}}_{\text{3}}.$ (b)$1\times {10}^{-7}\mathrm{MHCl}>1\times {10}^{-7}{\text{MCHHCOOH}}_{\text{3}}\text{COOH}$