Question

In a thermos flask,there is a vacuum between two glass tubes.what is the importance of the vacuum

Answer 1

It doesn't allow heat to move which the air therefore if there is no air then there is no problem

Answer 2

In the experiment explaining about respiartaion involves thermoflask and delivery results, for the creation of vaccum as by $\textbf{absorbtion of CO2}$ by the chemical.

This absorbtion of carbon-dioxide gas result for creation of vaccum, which results to creation of a LP area which results to transfer of water from HP area.