Question

Which is more soluble? $LiF$ or $KF$

• A.
• B.
• C. Same
• D. Data Insufficient

Answer 1

The correct option is B

It can be solved by using Fajan's Rule.

Here is another approch

In the example , $r_{+}$ $\approx$ $r_{-}$

In such cases,as cationic size increases,both lattice energy and hydration enthalphy decreases.

But,lattice energy will decrease faster.

Thus,$LiF$ is less soluble than $KF$