Question

Of the two solvent $H_{2}O$ and $D_{2}O$, $NaCl$ dissolves:

• A. equally in both solvents
• B. only in $H_{2}O$ but remains insoluble in $D_{2}O$
• C. more in $D_{2}O$
• D. more in $H_{2}O$

Answer 1

The correct option is D more in $H_{2}O$

$NaCl$ (and other ionic compounds) dissolve more in $H_{2}O$ than in $D_{2}O$ as the dielectric constant of $H_{2}O$ $\left(78.39\right)$ is higher than the dielectric constant of $D_{2}O\left(78.06\right)$. This is due to lower molar mass of $H_{2}O$ as compared to that of $D_{2}O$.