Question

Which of the following statements are correct?
(A) Both $LiCl$ and $MgC{l}_2$ are soluble in ethanol.
(B) The oxides $L{i}_{2}O$ and $MgO$ combine with excess of oxygen to give superoxide.
(C) $LiF$ is less soluble in water than other alkali metal fluorides.
(D) $L{i}_{2}O$ is more soluble in water than other alkali metal oxides.
Choose the most appropriate answer from the options given below:

• A. (A), (C) and (D) only
• B. (B) and (C) only
• C. (A) and (C) only
• D. (A) and (D) only

Answer 1

The correct option is C (A) and (C) only

(A) Both $LiCl$ and $MgC{l}_2$ are covalent in nature due to high polarizing power of $L{i}^{+}$ and $M{g}^{+2}$ ions, according to fajan's rules.
Hence, they are soluble in ethanol.
(B) Oxides of $L{i}_{2}O$ and $MgO$ do not form superoxide, as they are unable to stabilize the large superoxide ion.
(C) $LiF$ is least soluble among all other alkali metal fluorides due to high lattice energy of LiF
(D) $L{i}_{2}O$ is least soluble among all other alkali metal oxides also due to high lattice
Hence, Statements (A) and (C) are correct.