Question

If 2.38 mol of a gas has a volume of 120.0 mL, what is the volume of 1.97 mol of the gas at the same temperature and pressure?

Answer 1

According to the Avogadro's law, equal volumes of all gases contain equal number of moles under the same conditions of temperature and pressure.

Here the initial volume,
`V_(1) = 120.0 mL`

Initial moles of the gas,
`n_(1)=2.38 mol`

Final volume of the gas
`V_(2) = ?`

Final moles of the gas
`n_(2)= 1.97 mol`

Plugging in the Avogadro's equation,

`(V_(1))/(n_(1)) = (V_(2))/(n_(2))`

`(120.0 mL)/(2.38 mol) = (V_(2))/(1.97 mol)`

`V_(2) = 99.33 mL`

Therefore the 1.97 mol of the gas occupies 99.33 mL at constant temperature and pressure.