Question: how to find how many moles of gas are present?
Answer: To find the mole count, divide the mass in grams by 2.016. For example, if the mass of the hydrogen gas is 0.5 grams, then n equals 0.2480 moles. Convert the temperature T into Kelvin units by adding 273.15 to the temperature in Celsius. Use the ideal gas equation (PV=nRT) to solve for pressure.