Molar Mass and Molar Volume

Given the established relationship between volume and the number of particles, we should be able to calculate the molar mass of a substance in the gas state.  By measuring the mass of the gas and the volume occupied by the gas, the molar mass can be determined by:

STEP 1 - Convert the volume to number of moles using 22.4L / mole.

                                        Mass of gas
STEP 2 - Calculate        ------------------    which provides g/mol for the substance.
                                        Moles of gas


HW: Unit 5/8 Exam Review; Journal entry - complete the following:

1. What is the difference between an empirical formula and a molecular formula? 
2. Explain how we can find the molar mass of a substance in the gas state. 
3. Give an example problem for finding the molar mass of a substance.
4. Given the empirical formula and the molar mass, how can we determine the molecular formula of a substance (#10 on the first journal entry of the semester)?