Question

how to solve for a 28.4 L sample of methane gas is heated from 35.0° C to 76.0° C. The initial pressure of the gas is 1.00 atm at 35.0° C. Assuming constant volume, what is the final pressure of the gas?

OK, I did the following:

P₁ = 28.4 L P₂ = ?
T₁ = 41.0◦C T₂ = 35.0◦C
+273.15K= +273.15 K=
314.2K 308.2K

P₁T₁ = P₂
T₂

(28.4 L)(314.2 K) = 29.0 L
(308.2 K)

Do my answer looks correct which is 29.0 L

Answer 1

The question is asking for pressure so 29.0 L cannot be correct.

P1/T1 =P2/T2 where P is the pressure and T is the temperature in kelvin.

35.0C is (273.15+35.0) K
=308.15 K

76.0C is (273.15+76.0) K
=349.15 K

P1=1.00 atm

so

1.00 atm / 308.15 K
= P2 / 349.15 K

P2 = 1.133 atm

which is 1.13 atm to 3 sig figs (the starting pressure is to 3 sig figs)