chemistry
posted by Jamie on .
Three gases (8.00 of methane, 18.0 of ethane, and an unknown amount of propane, were added to the same 10.0L container. At 23.0 C , the total pressure in the container is 3.60 atm. Calculate the partial pressure of each gas in the container.

Use PV = nRT and calculate pressure for methane. Convert 8.00 (WHAT) to moles.
Do the same for 18.0 WHAT ethane.
Then partial pressure CH4 + partial pressure ethane + partial pressure unknown = 3 atm. 
16

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 your partial pressure for methane! You can do the same thing for ethane which has a chemical formula of C2H6. To solve for the partial pressure of the unknown gas you can use the formula: Ptotal=Pmethane+Pethane+Punknown... Your Ptotal is given as 3.60atm so just rearrange and for your unknown partial pressure. Hope this helps anyone else who needed this information!! :)

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