Q1.
Do you know that sodium is a metal which is stored in kerosene because it reacts vigorously with oxygen and water. A lot of heat is generated in the reaction. Storing sodium in kerosene prevents its exposure to moisture and air. Can you predict the nature of its oxide?
Answer
Sodium oxide will be basic in nature, because sodium is a metal and metal oxides are basic.
Sodium (a metal) + oxygen → sodium oxide
Sodium oxide + water → a solution that turns red litmus blue
So the oxide of sodium is basic.
Sodium oxide + water → a solution that turns red litmus blue
So the oxide of sodium is basic.
Why it happens: you have just seen magnesium — a metal — give a basic oxide. The rule holds for metals generally, so without doing any experiment you can predict the answer for sodium. This is how a scientific generalisation is used: prove it once carefully, then apply it.
Caution: never handle sodium yourself. It reacts so violently with the moisture of the air and with water that it catches fire — which is exactly why it is kept under kerosene, where neither air nor water can reach it.