A container has a volume of #15 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?

1 Answer
Sep 8, 2016

7.2 moles of gas must be released from the container.

Explanation:

Let's use 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.

• Identify your known and unknown variables:

#color(orange)("Knowns:"#
#v_1#= 15 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=(12cancelLxx9mol)/(15\cancel"L")# = # 7.2 mol#