Chemistry - Complete P-block Question with Solution | TestHub

A. The stability of $+3$ oxidation state decreases down the group for Group 13 elements due to the inert pair effect. Thus, $G{a}^{3+}$ is more stable than $G{a}^{+}$, but $I{n}^{+}$ is more stable than $I{n}^{3+}$. So, statement A is incorrect.

B. The basicity of hydrides ($N{H}_3$, $P{H}_3$, $As{H}_3$, $Sb{H}_3$) decreases down the group because the size of the central atom increases, reducing the electron density and hence the ability to donate a lone pair. Therefore, $Sb{H}_3$ is the weakest Lewis base. So, statement B is correct.

C. $NO$ and $N{O}_2$ are odd-electron species. $Cl{O}_2$ also has an odd number of valence electrons. These odd electrons reside in molecular orbitals, not necessarily hybrid orbitals. So, statement C is incorrect.

D. In $(Si{H}_3{)}_{3}NCS$, the nitrogen atom can form a dative bond with silicon due to the availability of d-orbitals on silicon. $N_2{O}_5$ has dative bonds from nitrogen to oxygen. So, statement D is correct.

The final answer is B, D