Question

A container has a volume of `21 L` and holds `14 mol` of gas. If the container is compressed such that its new volume is `7 L`, how many moles of gas must be released from the container to maintain a constant temperature and pressure?

Answer 1

9.33 moles

Explanation:

Assuming ideal gas behavior where n = PV/RT , with a constant temperature and pressure, the ratio of the volume change in L is the same as the ratio of the change in the total number of moles of gas in the container.
`(n_1*(PV)/T)_1 = (n_2*(PV)/T)_2`

`(n_2)/(n_1) = (V_2/(V_1)`

`(n_2)/(14)/ = (7/21)`

`(n_2) = (7/21)*(14)` = 4.67 moles

SO, to retain 4.67 moles from the original 14, 9.33 moles of gas must be released.