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 airtight 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.

AcademicChemistryNCERTClass 6

(a) The tiny bubbles appeared before the water started to boil since the air dissolved in water. Once the water started to boil, the air dissolved in water escaped in the form of bubbles.

(b) Paheli had boiled the water completely where the air from the water had escaped out, so reheating the cooled boiled water will not make any tiny bubbles as there is no air present in it.
Updated on 10-Oct-2022 13:20:23