we can use the combined gas law equation for this question.
[tex] \frac{PV}{T} = k [/tex]
where P - pressure
V - volume
T - temperature in kelvin
and k is constant
therefore
[tex] \frac{P1V1}{T1} = \frac{P2V2}{T2} [/tex]
parameters for the STP conditions are on the left side and parameters for the given instance
T1 - standard temperature - 273 K
T2 - 18 °C + 273 = 291 K
P1 - standard pressure - 1 atm
substituting the values in the equation
[tex] \frac{1 atm * V}{273K} = \frac{1.2 atm*3.94L}{291K} [/tex]
V = 4.4 L
new volume STP is 4.4 L
