Question

Non-metallic oxides are __________ in nature.
A. Acidic
B. Basic
C. Neutral
D. Both A and B

Answer 1

Hint: Solutions of non-metallic oxides when tested, turns litmus solution red which is a sign of solution being acidic in nature. $C{O_2}$ and $S{O_2}$ are examples of non-metallic oxides.

Complete step by step solution:
Non-metallic oxides form stable anions in aqueous solutions. If the anions are stable that means that they are ready to give out hydrogen ions. So when non-metallic oxides dissociate in water it makes an acidic solution. Thus, non-metallic oxides are acidic. For example, $C{O_2}$ and $S{O_2}$ are non-metallic oxides and are acidic. Their solutions turn the litmus solution red. Carbon dioxide reacts with water to form carbonic acid. The reaction is as follows:

$C{O_2} + {H_2}O \leftrightarrow {H_2}C{O_3}$

When water is in chemical equilibrium with the atmosphere, carbon dioxide reacts to form carbonic acid. This is also very important in chemical weathering of rocks. Rain water is mostly in chemical equilibrium with the atmosphere which makes the rain water acidic. Thus we can say that option A is the correct choice.

Note: Many times $CO$ is called neutral but it occurs that it is a very weak acid in aqueous solutions. When non-metallic oxides mix with water, it forms an oxyacid ions which are electronegative and readily dissociates to give hydrogen ions, thus acidic nature.