Question

Among the following, the correct statement is

• A. The density follows the order, Cs$^+$>Rb$^+$>Li$^+$>Na$^+$
• B. The solubility in water follows the order, Cs$_2$CO$_3$>K$_2$CO$_3$>Na$_2$CO$_3$>Li$_2$CO$_3$
• C. The first ionization potential follows the order, Li$^+$>K$^+$>Na$^+$>Cs$^+$
• D. The melting point follows the order, MgCl$_2$>BeCl$_2$>CaCl$_2$>SrCl$_2$

Hint:

The solubility of salts in water typically increases as the ionic radius of the cation increases, reducing the lattice energy.

Answer 1

The Correct Option is B

Step 1: Analyzing the order of solubility.
The solubility of alkali metal carbonates in water increases as the size of the cation increases. Larger cations like Cs$^+$ and K$^+$ form weaker ionic bonds with the carbonate ion, making the compounds more soluble in water.
Step 2: Conclusion.
Thus, the correct order for solubility in water is Cs$_2$CO$_3$>K$_2$CO$_3$>Na$_2$CO$_3$>Li$_2$CO$_3$, corresponding to option (B).