The following experiment is used to determine the amount of helium gas in a container. the volume of the container is 4.55 l, the height of the mercury gap is 500. mm, the ambient temperature is 20.°c, and the atmospheric pressure is 771 torr. determine the pressure in the container, the number of moles of gas, and the mass of the gas. pressure in the container 1.67 correct: your answer is correct. atm number of moles of gas .316 correct: your answer is correct. mol mass of the gas 1.264 correct: your answer is correct. g