Question

At 291 K, the equivalent conductivities at infinite dilution of $N{H}_{4}Cl$, $NaOH$ and $NaCl$ are $129.8$, $217.5$ and $108.9$ S $c{m}^{2}e{q}^{-1}$ respectively. The equivalent conductivity at infinite dilution of $N{H}_{4}OH$ is:

• A. $208.4Sc{m}^{2}e{q}^{-1}$
• B. $238.4Sc{m}^{2}e{q}^{-1}$
• C. $283.4Sc{m}^{2}e{q}^{-1}$
• D. None of these

Answer 1

Answer: (B)

$238.4Sc{m}^{2}e{q}^{-1}$

Equivalent conductance of $N{H}_{4}OH$ = Equivalent conductance of $N{H}_{4}Cl$+$NaOH$-$NaCl$

$=129.8+218.4-108.9$

Equivalent conductance of $N{H}_{4}OH=239.3$

Therefore, option B is the correct answer.