Paheli kept some water in a beaker for heating. She observed that tiny bubbles appeared before the water started to boil. She boiled the water for about 5 minutes and filled it in a bottle up to the brim and kept the bottle air tight till it cooled down to room temperature
(a) Why did the tiny bubbles appeared ?
(b) Do you think tiny bubbles will appear on heating the water taken out from the bottle? Justify your answer.

Explanation

(a) Air is dissolved in water in the form of oxygen. Tiny bubbles are formed, when air present in the waterscape on boiling it.So, tiny Bubbles appeared due to the evolution of air dissolved in water.

(b) No, tiny Bubbles will not appear as there is no dissolved air in this water.