A container has a volume of 19 L and holds 8 mol of gas. If the container is compressed such that its new volume is 5 L, how many moles of gas must be released from the container to maintain a constant temperature and pressure?

Apr 23, 2016

By The equation of state for real gas we know

$P V = n R T$

Where
P = Pressure, V = Volume, n = number of moles of gas , T = Absolute temperature of the gas and R = universal gas constant.
In our case P and T are constant in both the case

So $V \propto n$
Here ${V}_{1} = 19 L \mathmr{and} {V}_{2} = 5 L$
n_1=8mol and n_2 =?
${n}_{2} / {n}_{1} = {V}_{2} / {V}_{1} \implies {n}_{2} = {n}_{1} \times {V}_{2} / {V}_{1} = 8 \times \frac{5}{19} \approx 2.1 m o l$

So No of moles of gas to be released $= {n}_{2} - {n}_{1} = 8 - 2.1 = 5.9 m o l$