Calculate the Pressures of H2 and He: Are answers correct?

[blackjack18]

A mixture of 1.00 g of H2 and 1.00 g of He is placed in a balloon of volume 1.0 L when filled with these gases at 27 deg C.

A) calculate the partial pressure of each gas and the total pressure

pressure of H2-12.315 atm?
pressure of He-6.158 atm?

B) calculate the mole fraction of He in the mixture.


I need help with B

 

[Redbelly98]

(A) Looks right

(B) Start with how many moles of each gas are present.