I need help with the steps in solving the following for final tomorrow. 1. A gas has a density of 1.54g/L at 1.14atm and 15C. How do I calculate the molar mass of the gas? 2. What is the temperature in degrees Celsius of 0.0250 mole of hydrogen gas if it occupies 665mL at 715 torr? 3. Calculate the heat of vaporization of zinc if 393kJ is required to vaporize a 223 gram sample.