Question

Which one of the following is a basic oxide:
$\left(1\right)N_2{O}_5$

$\left(2\right)I{n}_2{O}_3$
Enter the correct number of the basic oxide.

Answer 1

The acidic oxides and the basic oxides when dissolved in water form acids and bases, respectively. For the given compounds, $N_2{O}_5$ forms $HN{O}_3$ (an acid) and $I{n}_2{O}_3$ forms $In(OH{)}_3$ (a base) when dissolved in water. A general rule of thumb is that non-metals tend to form acidic oxides whereas metals form basic oxides. Indium is a metal present in the 13th group of the periodic table and hence forms a basic oxide. Nitrogen on the other hand forms an acidic oxide. Also, the metallic property increases down a group and decreases when moving left to right in a period. Hence, gallium (Ga) and aluminium(Al), which are present just above Indium form amphoteric oxides, whereas boron (B) forms acidic oxides. A similar trend is observed in case of nitrogen family. The nature of oxides changes from acidic to amphoteric and finally basic. Since, indium has more metallic character than nitrogen, $I{n}_2{O}_3$ is more basic than $N_{2}O5$.