Question

Which of the following compounds has the minimum cation to anion size ratio?

• A. $CsF$
• B. $LiI$
• C. $LiF$
• D. $CsI$

Answer 1

The correct option is B $LiI$

The given anions are $F^{-}$ and $I^{-}$ and the size (R) order is $R_F<R_I$

The given cations are $L{i}^{+}$ and $C{s}^{+}$ and the size (R) order is $R_{Li}<R_{Cs}$

For the cation to anion ratio to be minimum, the compound must have a large anion and a small cation. Here, $I^{-}$ is the largest anion and $L{i}^{+}$ is the smallest cation.
Therefore, $LiI$ has the minimum cation to anion size ratio.