At 55C, what are the partial pressures of He and Ar and what is the total pressure in the flask?

Question

The 225mL flask contains 0.53g o He and 0.105g of Ar.

Answer 1

From the ideal gas law, P=nRT/V where n is number of moles (=mass/molecular weight) and R is the universal gas constant = 8.3145 J/mole-degK.
Remembering the rare gas molecules are monatomic:
For the Ar, P = R*.105/39.9476613*(273.15+55) / .225 = 31873 Pa.
For the He, P = R*.53/4.00026018*(273.15+55) / .225 = 1606624 Pa.
Total =1638495 Pa.