initial values

[Karina Kong 2H]

In PV=nRT, if you have to solve for the number of moles and are given the initial and final volume which do you use?

[LNgo 1G]

I believe you use the initial volume because you are trying to find the number of moles at the beginning of the process.

[Timmy Nguyen Dis 1I]

Yes use the initial.

[Zaynab Hashm 2I]

usually in the question, the initial values are given for both P and V, so make sure to use all the initial values (of all variables) at once in the equation to find n

[Pegah Nasseri 1K]

It depends on the values you've been given. If you've been given the initial pressure and the initial temperature, then use the initial volume to find the number of moles. Usually, you will only have been given all the initial values and will thus calculate the number of moles using the initial volume. The question should make it pretty clear what values you have for what variables.

[Kallista McCarty 1C]

I think you use the initial!

[Orrin Zhong 4G]

It depends on whether the other parameters (pressure, temperature) are in their initial states or their final states. Then you would choose the appropriate volume to plug into PV = nRT.