Question

Which of the following oxide is of acidic nature.

• A. $B_2O_3$
• B. $Al_2O_3$
• C. $Ga_2O_3$
• D. $In_2O_3$

Answer 1

Answer: (A)

$B_2O_3$

Answer 2

$B _{2} O _{3}$ is the acidic oxide. On moving down the group 13, the nature of oxide changes from acidic to basic.

$\underbrace{ B _{2} O _{3}}_{\text {Acidic }} \underbrace{ Al _{2} O _{3} \text { and } Ga _{2} O _{3}}_{\text {Amphoteric }} \underbrace{ In _{2} O _{3} \text { and } Tl _{2} O _{3}}_{\text {Basic }}$

Acidic character of boron oxide may be explained on the basis of small size of boron. Due to small size there is high positive charge density on atom.