To theoretically calculate the limiting molar conductivity of weak acetic acid () via Kohlrausch's l — Electrochemistry Chemistry Question
Question
To theoretically calculate the limiting molar conductivity of weak acetic acid ($\Lambda_{CH_3COOH}^\circ$) via Kohlrausch's law, the limiting molar conductivities of standard $CH_3COONa$ and $HCl$ are provided. The $\Lambda_m^\circ$ of which additional strong electrolyte is strictly required to complete the calculation?
💡 Solution & Explanation
According to Kohlrausch's Law, $\Lambda_{CH_3COOH}^\circ = \lambda_{CH_3COO^-}^\circ + \lambda_{H^+}^\circ$. We are given $\Lambda_{CH_3COONa}^\circ = \lambda_{CH_3COO^-}^\circ + \lambda_{Na^+}^\circ$ and $\Lambda_{HCl}^\circ = \lambda_{H^+}^\circ + \lambda_{Cl^-}^\circ$. Adding these gives $\lambda_{CH_3COO^-}^\circ + \lambda_{H^+}^\circ + \lambda_{Na^+}^\circ + \lambda_{Cl^-}^\circ$. To isolate acetic acid, we must subtract the contributions of $Na^+$ and $Cl^-$, which requires the limiting molar conductivity of $NaCl$.