Question

Identify the incorrect order against the property given in brackets

• A. BeCO$_3$<MgCO$_3$<CaCO$_3$<SrCO$_3$ (Thermal stability)
• B. BeSO$_4$>MgSO$_4$>CaSO$_4$>SrSO$_4$ (Solubility in water)
• C. Li$_2$CO$_3$>Na$_2$CO$_3$>K$_2$CO$_3$>Rb$_2$CO$_3$ (Thermal stability)
• D. BeCO$_3$>MgCO$_3$>CaCO$_3$>SrCO$_3$ (Solubility in water)

Hint:

For Group 1 and 2 compounds: Thermal Stability of carbonates, nitrates, and hydroxides increases down the group. Solubility: For salts with small anions (e.g., F$^-$, OH$^-$, CO$_3^{2-}$), solubility generally decreases down the group. For salts with large anions (e.g., SO$_4^{2-}$, I$^-$, NO$_3^-$), solubility generally increases down the group (with the notable exception of Group 2 sulphates, which decrease).

Answer 1

The Correct Option is C