Question

What is the molar volume of 46.00 grams of nitrogen gas?

Answer 1

Molar volume problems should provide some information about temperature and pressure, that is the only way to determine a substance's molar volume.

Starting from the ideal gas law, `PV = nRT`, the expression of an ideal gas' molar volume is

`PV = nRT -> (nRT)/P -> V/n = (RT)/P = V_(molar)`

If we take STP conditions - 273.15 K and 1.00 atm, the volume occupied by 1 mole of gas will be

`V/(1 mol e) = (0.082(L * atm)/(mol * K) * 273.15K)/(1.00 atm) = 22.4L/(mol) = V_(molar)`

So, if we have more moles of a gas, the volume occupied will be bigger at STP:

`n_(N_2) = m/(molar.mass) = (46.0g)/(14.0g/(mol)) = 3.29` moles. So,

`V = n * V_(molar) = 3.29 mol es * 22.4L/(1 mol) = 73.7L`