A sample of gas has an initial pressure of 1.50 atm at a volume of 3.40 L at a temperature of 20.0°C. ?

(3.40 L) / (20.0 + 273.15) K x (20.0 + 10.0 + 273.15) K x (1.50 atm / 2.50 atm) =

2.11 L

PV = nRT

Use a value of the gas constant in L-atm/deg-mol (it's 0.08206) and remember to use degrees K rather than degrees C.  So, in the first, calculation, T = 293.15 K and in the second, T = 303.15 K

Solve for n (the number of moles) apparently.  n = PV/RT.

Similarly for the second question, solve for V2 but remember that V2 = V1(P1/P2)(T2/T1).

Hint: pressure * volume = R * amount of gas * temperature (absolute)

R is a constant, for all gases. It depends only on the type of units you use.

Same troll question.  Same troll with a different account.  New troll day.  DON'T FEED THE TROLLS folks.