Question

A container has a volume of `18 L` and holds `9 mol` of gas. If the container is compressed such that its new volume is `12 L`, how many moles of gas must be released from the container to maintain a constant temperature and pressure?

Answer 1

`color(blue)(" 6 moles of gas must be released."`

Explanation:

The answer can be determined by using Avogadro's law:

`v_1/n_1 = v_2/n_2`

The number 1 represents the initial conditions and the number 2 represents the final conditions.

Let's identify our known and unknown variables.

`color(magenta)("Knowns:"`
`V_1`= 18 L
`V_2`= 12 L
`n_1`= 9 mol

`color(blue)("Unknowns:"`
`n_2`

Rearrange the equation to solve for the final number of moles:

`n_2=(V_2xxn_1)/V_1`

Plug in your given values to obtain the final number of moles:

`n_2=(12 cancelLxx9mol)/(18\cancel"L")` = `6 mol`