What pressure will be exerted by 2.01 mol hydrogen gas in a 6.5 l cylinder at 20 c?
You can answer this question using the ideal gas law:
PV=nRT.
P = Pressure
V = volume
n = Number of moles
R = Real Gas Constant (with units equal to the PV and T you are
using)
T = Temperature
In your problem, you want to solve for P, so the equation would
read
P=(nRT)/V
This would look like
P = (2.01moles)(8.314 J/mol K)(273K+20K)/6.5L
After the units cancel, this leaves you with 753 J/L, which can
be converted. For example:
1 J = 1 Pa m^3, which is equal to 1000 Pa L
So 753 J/L = 753,000 Pa L / L. Liters cancels so you are left
with 7530 hPa (753000 Pa)
This is roughly 7 atm.