Question

Which is true statement about $D_{2}O$ and $H_{2}O$?

• A. $D_{2}O$ has lower dielectric constant than $H_{2}O$
• B. $NaCl$ is more soluble in $D_{2}O$ than $H_{2}O$
• C. Both are correct
• D. None of these

Answer 1

Answer: (A)

$D_{2}O$ has lower dielectric constant than $H_{2}O$

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 the lower molar mass of $H_{2}O$ as compared to that of $D_{2}O$.

Due to this, $NaCl$ (and other ionic compounds) dissolve more in $H_{2}O$ than in $D_{2}O$.