sciencechemistry
posted by Bryan on .
please anwser soon, a rigid 4.10L flask contains a mixture of 1.25 moles of H2, 0.250 mole of O2, and sufficient Ar so that the partial pressure of Ar in the flask is 1.00 atm. The temperature is 63.5 degrees C
A) Calculate the total pressure in the flask
B) calculate the mole fraction of H2 in the flask
C) calculate the density g/L of the mixture in the flask.

A. Use PV = nRT and substitute mols H2; solve for P. Do th same with mols O2 and solve for P. Add pO2 + pH2 + pAr for Ptotal.
B. XH2 = nH2/total mols.
XO2 and XAr done the same way.
C. density = g/L
grams H2 = mols H2 x molar mass H2.
grams O2 = 
grams Ar = 
total g/total V = g/L = density. 
can u help me on part c a little more?