A 1.05 g sample of an ideal gas occupies 1.045 L at 20.0°C and 0.975 atm. What will be its volume at -8.6°C and 0.5 atm?

I used PV=nRT for this. substituted P for 0.5 then n for 1.05, R .0821 then T for 264.4 K

After doing this I got .0219 but it is incorrect, what am I doing wrong?

1 answer

N is not 1.05, that is the mass in grams.

do this:

PV=nRT
PV/T=nR for ideal gasses, nR is a constant.
At the second conditions,
PV/T=nR Hmmm. One is lead immediatlely to the combined gas law

P1V1/T1=P2V2/T2
solve for V2