chem
posted by alex .
an empty container has a mass of 658.57g. It has a mass of 659.45g after it has been filled with nitrogen gas at a pressure of 790 torr and a temperature of 15 deg C. When the container is evacuated and refilled with a certain element at a pressure of 745 torr and a temp of 26 deg C, it has a mass of 660.96g. What is the element?

Use PV = nRT to solve for V of the container with N2 gas.
Use PV = nRT with the unknown gas to determine n, then n = grams/molar mass to determine molar mass and from there the identity of the unknown gas.