Heres a problem on a take home quiz im doing, but i cant figure out how to get past the first step?! The density of helium gas at 0°C is 0.179 kg/m^3. The temperature is then raised to 100°C, but the pressure is kept constant. Assuming that Helium is an ideal gas, calculate the new density of the gas. Heres the equations i have: P1V1 / T1 = P2V2 / T2 In order to work this equation i need volume, but i have a density, heres the equation i think i need: roe = m / V (density = mass / volume) How do i work this if i dont have mass or volume?!