1. The problem statement, all variables and given/known data A mixture of He, Ne, and Ar has a total pressure of 0.80 atm and is found to contain 0.55 mol He, 0.94 mol Ne, and 0.35 mol Ar. What is the partial pressure of each gas in atm? 2. Relevant equations Partial pressure for a gas is equal to the mole fraction of the gas multiplied by the total pressure. 3. The attempt at a solution The total moles of gases: 0.55 + 0.94 + 0.35 = 1.84 moles. Helium has a mole fraction of .55/1.84 or 29.89%. 29.89% of 0.80 atm is 0.239 atm. Neon has a mole percent of 51.08%. It therefore has a partial pressure of 0.4086 atm. Argon has a partial pressure of 0.152 atm. However, my answers are incorrect according to the key. What gives?