Question

Nitrates of a group $I$ metals (except $Li$) decompose into the nitrites rather than oxides. This may most probably due to the fact that:

• A. doubly charged anions like $C{O}_3^{2-}$ and not singly charged anions like nitrates decompose to give oxides
• B. $O^{2-}$ is doubly charged and hence would make the salt less stable than singly charged nitrite $\left({N{O}_2}^{-}\right)$ ion
• C. nitrite anion has approximately same size as that of group I cations
• D. group I metal ions have relatively larger size compared to that of ${N{O}_2}^{-}$ ion

Answer 1

Answer: (C)

nitrite anion has approximately same size as that of group I cations

The size of nitrite anion is approximately similar to that of group I cations. Hence the close packing of metal ions and nitrite ions is efficient. Hence, nitrites are stable.