Question

Which of the following statements are correct? I. Liquid sodium metal is used as coolant in fast breeder nuclear reactor II. LiCl is deliquescent III. LiF and CsI have low solubility in water

• A. I, III only
• B. II, III only
• C. I, II only
• D. I, II, III

Hint:

Li compounds often behave differently because lithium ion is very small and highly polarizing.

Answer 1

The Correct Option is D

Step 1: Check statement I.
Liquid sodium has very high thermal conductivity and carries heat efficiently, so it is genuinely used as a coolant in fast breeder nuclear reactors. Statement I is correct.
Step 2: Recall the meaning of deliquescent.
A deliquescent solid absorbs so much atmospheric moisture that it dissolves in the absorbed water.
Step 3: Check statement II.
The small, highly polarizing $\text{Li}^+$ ion makes LiCl strongly moisture absorbing, so LiCl is deliquescent. Statement II is correct.
Step 4: Recall the solubility balance.
Solubility depends on lattice energy versus hydration energy; when one ion is tiny or both ions are large, solubility drops.
Step 5: Check statement III.
LiF has a very high lattice energy from two small ions, while CsI has low hydration energy from two large ions, so both are poorly soluble. Statement III is correct.
Step 6: Combine.
All three statements hold, which is option 4.
\[ \boxed{\text{I, II, III}} \]