If the pressure exerted by a gas at 27.0 c in a vessel of volume 0.050 L is 4.00 atm, how many moles of the gas are pressure?

This is a problem to apply the ideal gas equation.

pV = n RT = > n = pV / RT

Where:

R is the Universal constant of gases = 0.082 atm*liter / K*mol

p = 4.00 atm

V = 0.050 liter

T = 27.0 + 273.15 = 300.15 K

n = pV / RT = 4.00 atm * 0.050 liter / (0.082 atm*liter/K*mol * 300.15K) = 0.0081 mol

Answer: 0.0081 mol