What is the pressure in atm of 3.02 g of H2 gas at 10.91 L and 291 K?

Answer 1

The Ideal Gas Law is most commonly written as PV = nRT where P is pressure, V is Volume, "n" is number of moles, R is the Ideal Gas Constant (selected based on the units we are working with), and T is absolute temperature. In this case, since we are asked for pressure, we can solve for P:

P = nRT/V

But we are not given the number of moles, instead we are given the mass of Hydrogen. But, we can look up the molar mass on the Periodic Table and we see it is 1.008 g/mole. So 3.02g/1.008g/mole = 2.996 moles

Since the units we have are atm, moles, K, and L we can look up the appropriate value of R in those units. It is 0.082057 (L atm)/(mole K) so:

P = (2.996)(0.082057)(291)/10.91 = 6.56 atm