JEE Chemistry 2023 Question with Solution

Given: Group-$13$ element oxides of the form $M_2O_3$ are compared.

Find: The most basic oxide among $Al_2O_3$, $Tl_2O_3$, $Ga_2O_3$ and $B_2O_3$.

As electropositive character increases down Group-$13$, the basic character of their oxides increases.

The order given in the solution is

Thus, among the given options, $Tl_2O_3$ is the most basic oxide.

Therefore, the correct option is B.

Given: Oxides of Group-$13$ elements are to be compared on basic character.

Find: Which oxide is most basic.

$B_2O_3$ is acidic, while $Al_2O_3$ is amphoteric. On moving down the group, metallic and electropositive character increases, so the oxides become more basic.

Therefore, among $B_2O_3$, $Al_2O_3$, $Ga_2O_3$ and $Tl_2O_3$, the oxide of thallium shows the highest basic character.

Hence, the most basic oxide is $Tl_2O_3$, so the correct option is B.