81. A sample of helium gas has been contaminated with argon gas. At 1 atm and 25°C, the density of t
問題詳情
81. A sample of helium gas has been contaminated with argon gas. At 1 atm and 25°C, the density of the mixture is 0.200 g/L. What isthe volume percent helium in the sample? (A) 90.0% (B) 97.5% (C) 80.3% (D) 2.5% (E) 99%