Gas law question

Question

A sample of nitrogen gas at 180 K has a pressure of 1.0 atm. When the temperature is increased to 360 K at constant volume, the new pressure will be

Answer 1

Use the formula:

P₁/T₁ = P₂/T₂

Solve for P₂:

P₂ = P₁T₂/T₁ = 1atm x 360K/180K = 2 atm

Answer 2

PV=nRT

1.0[atm]*V = nR(180K)

at const volume--assuming ideal gas of nitrogen without corrections:

V₁=V₂

so nRT₁/P₁ = nRT₂/P₂

i.e. T₁/P₁ = T₂/P₂

Provided units of P1 and P2 are same, as with Temps 1 and 2, we can use this

180/1.0 (K/atm) = 360/P₂ (K/atm)

The pressure will double... new pressure is 2.0 atm