A flask containing air ( open to atmosphere ) is heated from 300K to 500K . The fraction of air escaped to the atmosphere is about.

Options

A. 0.166
B. 0.4
C. 0.66
D. 0.33

Answer

C

Explanation

Suppose V is the volume of the flask
`( V_(1))/( T_(1)) = ( V_(2))/( T_(2)) `
or `V_(2) = V_(1) xx ( T_(2))/( T_(1)) = V xx( 500)/( 300) = ( 5)/( 3) V `
Increase in volume `= ( 5)/( 3) V - V = ( 2)/( 3) V `
% of air escaped `= ( 2)/( 3) V xx ( 100)/( V) = 66.7%`