JEE Main 2025 Apr 2 Shift 2, Chemistry Q15: Group 16 Elements: The Oxygen Family

Going down group 16, the stability of the +6 oxidation state decreases and the lower (+4) state becomes increasingly stable (inert-pair effect). $\mathrm{Te}{\mathrm{O}}_2$ has Te in the +4 state and is readily reduced to elemental Te, so it acts as an oxidising agent.

For the hydrides ${\mathrm{H}}_2\mathrm{E}$ of group 16, the E-H bond becomes longer and weaker as the central atom gets larger. The Te-H bond in $\mathrm{Te}{\mathrm{H}}_2$ is therefore very weak, allowing easy release of ${\mathrm{H}}^{+}$ and making the hydride strongly acidic.

$\therefore$ $\mathrm{Te}{\mathrm{O}}_2$ - oxidising ; $\mathrm{Te}{\mathrm{H}}_2$ - acidic.