8.3144721(15) means last two digits are +/-15, this is a way of giving accuracy of the constant.

But as you are correctly suggesting R is not needed to solve the question.

Oh I see... well, thanks Borek, never seen something like that before ^^

I'm really sorry, and I know that I must seem as dumb as a brick wall, but I don't understand how n1 = n2 will solve my question if I'm looking for the volume.

And if I do it without the R, would the equation be:

pV

n = -------

T

But am I able to just take the R out like that?

Ok... let's tidy up the whole thing, and don't worry if you don't understand at first glance

No one said you had to forget the R constant and write the equation without that... it's like writing a reaction without one of the products: there's something missing...

Anyway R doesn't actually need: doing some easy calculations you'll see that it's soon taken out.

As I said start from

, here's what I mean:

Start from this, now it should be much more clearer