Hi everybody, i'm having a little trouble with this stp and gas volume

ok heres what we should be aware with:

from kaplan book, they give an example of what seems to contradict this fact:

What is the molar mass of a 2L sample of gas that weighs 8g at a temp of 15C and a pressure of 1.5atm?

They do: V = (2L)(273/288)(1.5/1)

What they are doing is comparing the volume of the gas with the volume at STP (cool I get that), but why are they putting an increase in temp in the denominator? (as temp increases, volume increases is a fact) same for pressure (its reversed!) any insight would be great!

thnx!!

ok heres what we should be aware with:

**as Temp increases, volume increases, as pressure increases vol decreases**from kaplan book, they give an example of what seems to contradict this fact:

What is the molar mass of a 2L sample of gas that weighs 8g at a temp of 15C and a pressure of 1.5atm?

They do: V = (2L)(273/288)(1.5/1)

What they are doing is comparing the volume of the gas with the volume at STP (cool I get that), but why are they putting an increase in temp in the denominator? (as temp increases, volume increases is a fact) same for pressure (its reversed!) any insight would be great!

thnx!!