In order to find the number of moles in this question, we need to use the Ideal gas Law formula, which is the following formula:
PV = nRT
Where:
P = pressure, we will use it in atm, 36.0 kPa = 0.355 atm
V = volume in liters, 38 L
n = number of moles
R = gas constant, 0.082
T = temperature in kelvin, 82°C = 355 K
Now we add all these values into the formula:
0.355 * 38 = n * 0.082 * 355
13.49 = 29.11n
n = 0.46 moles of Oxygen gas