JEE Main 2022 — S Block Elements Question with Solution

$${\mathrm{Li}}_2\mathrm{O},{\mathrm{NaNO}}_2$$

As per NCERT lithium nitrate when heated gives lithium oxide, $${\mathrm{Li}}_2\mathrm{O}$$. Whereas other alkali metal nitrates decompose to give the corresponding nitrite.

$$4{\mathrm{LiNO}}_3⟶2{\mathrm{Li}}_2\mathrm{O}+4{\mathrm{NO}}_2+{\mathrm{O}}_2$$

$$2{\mathrm{NaNO}}_3⟶2{\mathrm{NaNO}}_2+{\mathrm{O}}_2$$

However, the decomposition product of $${\mathrm{NaNO}}_3$$ is temperature dependent process as shown in the below reaction.

$${\mathrm{NaNO}}_3\underset{500^{\circ }\mathrm{C}}{\stackrel{\Delta }{⟶}}{\mathrm{NaNO}}_2(\mathrm{s})+\frac{1}{2}{\mathrm{O}}_2(\mathrm{g})$$
                      $$\Delta \downarrow ,800^{\circ }\mathrm{C}$$
                      $${\mathrm{Na}}_2\mathrm{O}(\mathrm{s})+{\mathrm{N}}_2(\mathrm{g})+{\mathrm{O}}_2(\mathrm{g})$$

As the temperature is not mentioned, we can go by the answer. (C)