A desiccator of internal volume one litre containing `N_(2)` at 1 atm is partially evacuated to final pressure of `78mm` of Hg while `T` remains constant What is the volume of gas at this stage ?
(b) A lungful of air `(3.55 cm^(3))` is exhaled into a machine that measures lung capcity if the air is exhaled from lungs at a pressure of `1.08` atm at `37^(@)C` but the machine is a ambient conditions of `0.958` atm and `23^(@)C` what is the volume of air measured by the machine ? .

Explanation

The volume of vessel remains constant and some moles are given out
Thus given gas =1litre
`PV = nRT`
In lungs ` 1.08 xx (3.55)/(1000) = n xx 0.0821 xx 310`
In machine `0.958 xx V = n xx 0.0821 xx 296`
`:. V = 3.82 xx 10^(-3)` litre .