Question

A 642 mL sample of oxygen gas at 23.5°C and 795 mm Hg, is heated to 31.7°C and the volume of the gas expands to 957 mL. What is the new pressure in atm?
A) 0.723 atm
B) 0.932 atm
C) 3.05 atm
D) 5.19 atm

Answer 1

We can use the combined gas law equation to find the new pressure of the gas. 
$\frac{P1V1}{T1} = \frac{P2V2}{T2}$
where P - pressure 
V - volume
T - temperature 
parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation 
P1 - 795 mm Hg x 0.0013 atm/ mm Hg = 1.033 atm
T1 - 23.5 °C + 273 = 296.5 K
T2 - 31.7 °C + 273 = 304.7 K
substituting the values in the equation 
$\frac{1.033 atm *642 mL}{296.5K}= \frac{P*957mL}{304.7K}$
P = 0.712 atm 
the answer closest to this value is A) 0.723 atm
therefore answer is 
A) 0.723 atm