A container has a volume of #18 L# and holds #6 mol# of gas. If the container is compressed such that its new volume is #3 L#, how many moles of gas must be released to maintain a constant temperature and pressure?

1 Answer
Mar 21, 2018

Answer:

#5# moles

Explanation:

At constant temperature and pressure, we can use Avogadro's law, which states that

#Vpropn# or #V_1/n_1=V_2/n_2#

So, we need to find the new number of moles, and we can rearrange the equation into,

#n_2=n_1/V_1*V_2#

Now, we can substitute into the given values, and we get

#n_2=(6 \ "mol")/(18color(red)cancelcolor(black)"L")*3color(red)cancelcolor(black)"L"#

#=1 \ "mol"#

So, the new amount of moles will be #1 \ "mol"#.

In order to find the difference, #Deltan#, we use,

#Deltan=n_2-n_1#

#=1 \ "mol"-6 \ "mol"#

#=-5 \ "mol"#

So, five moles of the gas must be released.