A container has a volume of #4 L# and holds #2 mol# of gas. If the container is expanded such that its new volume is #14 L#, how many moles of gas must be injected into the container to maintain a constant temperature and pressure?

1 Answer
Aug 22, 2016

Answer:

7 moles of gas must be injected into the container.

Explanation:

The answer can be calculated 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.

Identify your known and unknown variables:

#color(brown)("Knowns:"#
#v_1#= 4 L
#v_2#= 14 L
#n_1#= 2 mol

#color(gray) ("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=(14 cancelLxx2mol)/(4\cancel"L")# = #7 mol#