When pure water boils vigorously, the bubbles that rise

• GS Water

When pure water boils vigorously, the bubbles that rise to the surface are composed primarily of

1. air
2. hydrogen
3. hydrogen and oxygen
4. water vapour

Answer

When you first start to boil water, the bubbles are basically air bubbles. These are bubbles formed from the dissolved gases in water. The solubility of gases decreases when the temperature is increases, and that is why the dissolved air bubbles come out from the water.

Then, as the boiling point of water is reached, water vapor starts to form in the form of bubbles. The molecules gain enough energy to transition from the liquid phase to the gaseous phase. These bubbles are water vapor.

The correct option is D.