JEE Main 2022 · 24 Jun · Shift 1 · Chemistry Q69

ChemistrySingle correct+4 / -1Question 69 of 90

Which of the following statements are correct ?

(A) Both LiCl and $\mathrm{MgCl_2}$ are soluble in ethanol.

(B) The oxides $\mathrm{Li_2O}$ and MgO combine with excess of oxygen to give superoxide.

(D) $\mathrm{Li_2O}$ is more soluble in water than other alkali metal oxides.

Choose the most appropriate answer from the options given below :

(A) and (C) only

(A), (C) and (D) only

(B) and (C) only

(A) and (D) only

Answer and worked solution

Official answer: A

Check each statement (diagonal relationship of Li and Mg).

(A) True: LiCl and $\mathrm{MgCl_2}$ are covalent enough to dissolve in ethanol.
(B) False: Li and Mg form normal oxides, not superoxides.
(C) True: LiF has a very high lattice energy, so it is the least soluble alkali metal fluoride.
(D) False: $\mathrm{Li_2O}$ is the least soluble alkali metal oxide.

(A) and (C).

(A)

Topics:Alkali metals Alkaline earth metals

JEE Main 2022 · 24 Jun · Shift 1, Chemistry question 69