Question

The molar conductivities of ${\wedge }_{NaOAC}^0$ and ${\wedge }_{HCl}^0$ at infinite dilution in water at ${25}^{0}C$ and 91.0 and $426.2Sc{m}^2/mol$ respectively. To calculate ${\wedge }_{HOAc}^0$, the additional value required is:

• A. ${\wedge }_{NaCl}^0$
• B. ${\wedge }_{H_{2}O}^0$
• C. ${\wedge }_{KCl}^0$
• D. ${\wedge }_{NaOH}^0$

Answer 1

The correct option is A ${\wedge }_{NaCl}^0$

According to kohlrausch law of independent migration of ions, the molar conductivity of an electrolyte

at infinite dilution is equal to the sum of the contributions of the molar conductivites of its ions.
Hence,
${\Lambda }_{HOAc}^{\infty }={\Lambda }_{H+}^{\infty }+{\Lambda }_{AcO-}^{\infty }={\Lambda }_{NaOAc}^{\infty }+{\Lambda }_{HCl}^{\infty }-{\Lambda }_{NaCl}^{\infty }$
Hence the additional value required is ${\Lambda }_{NaCl}.$

Hence, correct option is A.