Question

When a non-metal reacts with oxygen, it forms a non-metallic oxide. This non-metallic oxide when reacted with $H_{2}O$, form a substance, ‘X’ with pH value less than 7. Select the correct option regarding the substance, ‘X’.

• A. Acidic
• B. Basic
• C. Salt
• D. Neutral

Answer 1

The correct option is A

Acidic

Non-metals on reaction with Oxygen gas give rise to non-metallic oxides. These non-metallic oxides on reaction with ${\text{H}}_2\text{O}$ give acidic substance. For example, Sulphur (non-metal) is a non-metal. It forms ${\text{SO}}_2$ and ${\text{SO}}_3$ to convert into ${\text{H}}_2{\text{SO}}_4$. On a pH scale, acids always have a value which is less than 7.

$\text{S}+{\text{O}}_2\to {\text{SO}}_2$
${\text{2SO}}_2+{\text{O}}_2\to {\text{2SO}}_3$
${\text{SO}}_3+{\text{H}}_2\text{O}\to {\text{H}}_2{\text{SO}}_4$