Question

What pressure in Pascals will be exerted by 4.78 grams of oxygen gas in a 2.5-liter container at 20 C?

Answer 1

`P~=150*kPa`

Explanation:

From the Ideal Gas equation..........

`P=(nRT)/V=((4.78*g)/(32.00*g*mol^-1)xx0.0821*(L*atm)/(K*mol)xx293*K)/(2.50*L)`

`=1.44*atm-=1.44*atmxx101.3*kPa*atm^-1=145.6*kPa`

Note that you SIMPLY MUST KNOW that `H_2, O_2, N_2, F_2, Cl_2` are binuclear as the elements. In fact all the elemental gases (at RT) EXCEPT for the Noble Gases are bimolecular.