Question

Which of the following is not an acidic anhydride?

• A. $N_2{O}_3$
• B. $P_2{O}_5$
• C. $N_2{O}_4$
• D. $B{i}_2{O}_3$

Answer 1

The correct option is D $B{i}_2{O}_3$

$B{i}_2{O}_3$ is not an acidic anhydride.
The basic character of oxides increases with increase in the atomic size of element belonging to the nitrogen family. Oxides of N and P are acidic (except $N_{2}O$ and NO which are neutral), oxides of arsenic and antimony are amphoteric and bismuth oxide is more basic and less acidic.
$B{i}_2{O}_3+6HCl\to 2BiC{l}_3+3H_{2}O$
$B{i}_2{O}_3+6NaOH\to 2N{a}_{2}Bi{O}_3+3H_{2}O$