Question

A sample containing 4.80g of O2 gas has a volume of 15.0L. Pressure and temperature remain constant. What is the new volume if 0.500 mole of O2 gas is added?
Am I converting the 4.80 O2 into moles first? How do I do that?

Answer 1

yes. Use PV = nRT and solve for n, then add 0.500 to that and use PV =nRT again and solve for V. Since P and T remain constant you can use any number you which as long as you stay consistent with the two calculations (I would use 1 for P and 1 for T. n won't mean anything then but the answer will come out right. The 0.500 mole of O2 added must be at the same T and P as the original sample.)

Answer 2

a sample containing 4.80 g O2 of gas has a volume of 15.0 L. Pressure and temperature remain constant. What is the new voume if 0.500 mole O2 gas is added?