PV=nRT, molar mass and empirical formulae

What this note covers

1. The ideal gas equation and its variables
2. Choosing the right value of R and matching units
3. The combined gas law for changing conditions
4. Worked example: molar mass of a gas from PV = nRT
5. From percentage composition to empirical formula
6. From empirical formula to molecular formula using molar mass
7. How Section D examines gas and formula calculations, and what separates a top response

7 sections · 10 key terms & formulas · 6 common mistakes