M. Beaton

Take your methane first. Find the moles by dividing the mass (8.00g) by the molar mass (which can be found by the chemical formuls CH4 = 16.042g/mol). Then you can rearrange the ideal gas formula to solve for the pressure of methane (P=nRT/V). This is you...

First you have to find the moles of O2 and N2. To do this you must assume that this is a 100g sample. Therefore, 30.8g of nitrogen. Now you can find the moles of nitrogen by dividing this mass by nitrogen's molar mass: 30.8g/(14.01g/mol x 2) = 1.10moles N...

For anyone on Mastering Chemistry, I got the final answer as methane: 1.21atm, ethane: 1.45atm, and unknown: 0.940atm.