The monoatomic gas : He
In general, the gas equation can be written
[tex]\large {\boxed {\bold {PV = nRT}}}[/tex]
where
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.08206 L.atm / mol K
T = temperature, Kelvin
P 380.9 mmHg = 0.5 atm
T 20 C+273 = 293 K
We can find molar mass of gas :
[tex]\tt M(molar~mass(M)=\dfrac{mRT}{PV}\\\\M=\dfrac{8~g\times 0.082\times 293~K}{0.5~atm\times 96~L}\\\\M=4~g/mol[/tex]
monatomic gas means a single element, usually a noble gas. The noble gas element with mass 4 is He
