90. The partial pressure of CO2(g) is 0.22 atm and that of CO(g) is 0.44 atm in a mixture of the two gases at 25ºC. What is themass fraction of CO2 in the mixture? (atomic weight: C = 12 g/mol, O = 16 g/mol)
(A) 44%
(B) 56%
(C) 33.3%
(D) 66.7%
(E) 50%