An open flask contains air at `27^(@)C` Calculate the temperature at which it should be heated so that
(a) `(1)/(3)` rd of air measured at `27^(@)C` escapes out

Explanation

Let the initial number of moles of air at `27^(@)C (300 K) " be " = n`
Number of moles of air left when the air is heated to the temperature `T K = n - (n)/(3) = (2n)/(3)`
At constant pressure and constant volume,
`n_(1)T_(1) = n_(2) T_(2)`
or `n xx 300 = (2n)/(3) xx T`
or `T = 450 K = (450 - 273) = 177^(@)C`