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

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.