在标准状况下氢气和一氧化碳的混合气体7升,质量是2.25克,求氢气和一氧化碳的质量分数和体积分数?

n(H2) + n(CO) = 7/22.4 mol = 0.3125mol
2xn(H2)+28xn(CO) = 2.25g
两式连立,解得：n(H2) = 0.25mol,n(CO)=0.0625mol
V(H2) = 0.25x22.4L = 5.6L,V(CO) = 0.0625x22.4L = 1.4L
m(H2) = 0.25x2g = 0.5g,m(CO)= 0.0625x28g =1.75g
H2的质量分数= 0.5/2.25x100% =22.2%
CO的质量分数= 1.75/2.25x100% = 77.8%
H2的体积分数 = 5.6/7x100% = 80%
CO的体积分数= 1.4/7x100%= 20%