Chemistry 5

2. Particles are in constant motion
4. Overall enthalpy change in a reaction is equal to the sum of the enthalpy changes for the individual steps in the process.
9. enthalpy of products - enthalpy of reactants
10. Standard Temperature and Pressure
11. The temperature and pressure at which the solid, liquid, and gas phases co-exists.
12. Heat energy released; products lower
13. The change of a solid directly to a gas
14. Where substance indicates the critical temperature and critical pressure.
15. The amount of energy required to melt one mole of a solid

1. The amount of energy as heat needed to vaporize one mole of a liquid.
3. using Hess' law; process equals the sum of the energy difference of products minus the sum of the energy difference of the reactants
5. Heat energy is absorbed; products higher
6. Liquids that do not evaporate readily because of strong attractive forces between particles.
7. A graph of pressure and temperature that shows the conditions under which a substance exists.
8. The change of a gas directly to a solid.