A mixture of 1.24 g H2 and 1.51 g He is placed in a 1.00 L container at 28°C. How do you calculate the partial pressure of each gas and the total pressure?

1 Answer
Aug 15, 2016

#"We follow Dalton's Law of Partial Pressures........"# to give #P_"Total"=P_"dihydrogen"+P_"helium"=24.5*atm.#

Explanation:

#"Dalton's Law of Partial Pressures states:.........."#

In a gaseous mixture the pressure exerted by a component gas is the same as the pressure it would exert if it alone occupied the container.

The total pressure is the sum of the partial pressures.

Thus #P_"Total"# #=# #P_"dihydrogen"+P_"helium"#.

Assuming ideality, #P_"dihydrogen"# #=# #(nRT)/V# #=# #(1.24*g)/(2.016*g*mol^-1)xx0.0821*L*atm*K^-1*mol^-1xx301*Kxx1/(1.00*L)=15.2*atm#

AND

#P_"helium"# #=# #(nRT)/V# #=# #(1.51*g)/(4.003*g*mol^-1)xx0.0821*L*atm*K^-1*mol^-1xx301*Kxx1/(1.00*L)=9.3*atm#

Thus #P_"Total"# #=# #(15.2+9.3)*atm# #=# #24.5*atm#