There are two containers filled with gases.In both containers,gases are same temperature and pressure.The first container is 3 L and contains 0.9 moles of gases. The second container is 1 L.How many moles of gas are there in the second container?

Expert Answers

An illustration of the letter 'A' in a speech bubbles

This can be done by ideal gas law PV = nRT.


n1 = moles in gas 1 = 0.9

n2 = moles in gas 2


`R = 8.314`

`V1 = 3L`

`V2 = 1L`


For both cases pressure and temperature is same.And R is also same for both gases.

`PV = nRT`

`P/(RT) = n/V`

Since P/(RT) is same for both;

`(n1)/(V1) = (n2)/(V2)`

`n2 = (n1V2)/(V1)`

`n2 = 0.9*1/3`

`n2 = 0.3`


So in the other gas there are 0.3 moles.



  • Both gasses act as ideal gasses.



Approved by eNotes Editorial Team
An illustration of the letter 'A' in a speech bubbles

To solve for the number of moles of gas in the second container, apply Ideal Gas Law. The formula is:

`PV = nRT`

where P - pressure , V - volume , T - temperature, n -  number of moles and R - universal constant (R=8.3145J / mol K ).

The given in the first conatiner are V = 3L and n=9 moles. Substitute these to the formula above.

`P_1(3) = 0.9 (8.3145)T_1`

Then, isolate `P_1` and `T_1` since their values are unknown.

`P_1/T_1 = (0.9(8.3145))/3`

`P_1/T_1 = 2.49435`

And in the second container, the given is V=1 L. Substitute this to the formula of Ideal Gas Law.


Isolate `P_2` and `T_2` too.

`P_2/T_2 = (8.3145n)/1`

`P_2/T_2 = 8.3145n`

Note that the pressure and temperature of the gases inside the two containers are the same. So,

`P_1/T_1 = P_2/T_2`


Then divide both sides by 8.3145 to solve for n.


`n =0.3`

Hence, there are 0.3 moles of gases in the second container.

Approved by eNotes Editorial Team
Soaring plane image

We’ll help your grades soar

Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.

  • 30,000+ book summaries
  • 20% study tools discount
  • Ad-free content
  • PDF downloads
  • 300,000+ answers
  • 5-star customer support
Start your 48-Hour Free Trial