A 125 mL tank is charged with oxygen until the pressure is 75.0 atm at 25 degrees C.?

Question

Calculate the moles of oxygen in the tank.

a) 383
b) 4.57
c) 0.0505
d) 0.383
e) 0.00378

thanks

Answer 1

For an ideal gas PV=nRT
where
P = pressure (in atm)
V = volume (in L)
n = # of moles of gas
R = ideal gas law constant (0.082 atm-L/mol-K)
T = temperature (in Kelvin or degC+273.15)

so

n = PV/RT
= (75 atm)(0.125 L)/[(0.082 atm-L/mol-K)(298.15 K)]
= 0.383 mol

Please try to study first for your next homework.

Answer 2

Just use the ideal gas law: PV=nRT and solve for n. Be sure that your temperature is converted to K, and your volume to L. R will be 0.0821 L atm/mol K