posted by billystar on .
1. the molar mass of helium is 4.00 g/mol.
calculate the volume of 1 mol of helium at STP (T = 273, P = 1 atm)
what is the density of helium at STP?
2. the density of an ideal gas is 1.35 kg/m^3. if the temperature is Kelvin and the pressure are both doubled, find the new density of the gas.