Answer: P2 = 0.858 atm
Explanation:
Use the combined gas law: P1V1/T1 = P2V2/T2,
where the subscripts are the initial (1) and final (2) states. Temperature must be in Kelvin. We want P2, so rearrange the equation to solve for P2:
P2 = P1(V1/V2)(T2/T1)
Note how I've arranged the volume and temperature values: as ratios. Now it is easy to cancel units and see what is going to happen to the pressure if we lower the temperature. Since the pressure change is a function of (T2/T1), and we are lowering the temperature (T2), we'd expect this to decrease the pressure.
No information is given on volume, so we'll assume a convenient value of 1 liter. Now enter the data:
P2 = (0.917atm)*(1)*(322K/344K)
P2 = 0.858 atm
