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 #8 L#, how many moles of gas must be released from the container to maintain a constant temperature and pressure?

1 Answer
Sep 1, 2017

Answer:

See below

Explanation:

# v= 15L#
# n = 9#

According to Ideal Gas equation

#PV = nRT-----------(I)#

Where
#R# is a constant whose value depends
#P# is pressure
#V# is volume
#n# is moles
#T# is temperature

#P15 = 9TR#

Now moving on to the second condition

# v = 8L#
#n = ?#

#PV = nRT#

#P8 = nRT --------- (II)#

Dividing (I) and (II)

We have,

#(P15)/(P8) = (9RT)/(nRT)#

Since the given conditions are same for both the cases, These can be canceled out..... So we are left with

#(15)/(8) = (9)/(n)#

# 72/15 = n#

# n = 4.8#

Therefore 9 - 4.8 moles need to be removed

i.e #4.2 mol# to maintain the same pressure and temperature.