Moles of each gas...

Question

A mixture of 1.00 g H2 and 1.00 g He is placed in a 1.00 L container at 27 Celsius. Determine the mole fraction of each gas.

Answer 1

A mole fraction is represented as X_i = n_i/n_t where Xi is the molar fraction, n_i is the number o moles of gas i, and n_t is the total number of moles.

Our gases are given in grams so we need to convert these to moles:

1.0 g H2 x 1mol/2.00g = 0.5 mole

1.0 g He x 1mol/4.00g = 0.25 mole

Next, we need find X_i of each gas:

X_H2 = 0.5/(0.5 + 0.25) = 0.667

X_He = 0.25/(0.5 + 0.25) = 0.333