Question

Calculate the molar conductivity of water at infinite dilution (in Sm${}^2$ mol${}^{-1}$ ).

( molar conductivity of hydrogen ions and the molar conductivity of hydroxide ions at infinite dilution are $349.6\times {10}^{-4}$Sm${}^2$ mol${}^{-1}$ and $198.3\times {10}^{-4}$Sm${}^2$ mol${}^{-1}$ )

• A. $547.9$
• B. $647.9$
• C. $647.9\times {10}^{-4}$
• D. $547.9\times {10}^{-4}$

Answer 1

The correct option is D $547.9\times {10}^{-4}$

The molar conductivity of water at infinite dilution (in $S{m}^{2}mo{l}^1$ ) is ${\Lambda }_{H_{2}O}^o={\lambda }_{H^{+}}^0+{\lambda }_{O{H}^{-}}^0=349.6\times {10}^{-4}+198.3\times {10}^{-4}=547.9\times {10}^{-4}$.

It is equal to the sum of the molar conductivity of hydrogen ions and the molar conductivity of hydroxide ions at infinite dilution.