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| 5 steps to solving equilibrium problems | What is done? The effect on T, P or C in the system? What will the system do? What direction will be favoured (equation needed)? Outcomes? |
| Collision Theory | Reactions can oly happen when the reactant particles collide, but most collisions are NOT successsful in forming product molecules despite the high rate of collisions, due to nit having sufficient enery. Molecules collide with the correct orientation. |
| Factors affecting Rates | Temperature (Ek ave - number of collisions), Concentration (Aqueos or gas, increases number of collsions), Catalyst (Lowers Ea), Volume/Pressure (Gas, more collsions equals decrease in V), Surface Area (Number of collisions), Nature of reactants (bond forming slow) |
| Endothermic | Delta H=+ve, T decreases, KJ on L.H.S., Bond Breaking |
| Exothermic | Delta H= -ve, T increases, KJ on R.H.S., bond forming |
| Le Chatelier principle | If a chemical system at equilibrium is subject to change in conditions, the system will adjust to re-establish equilibrium in such a way as to partially counteract the imposed change |
| Factors affecting Equilibrium | Concentration, Pressure/Volume, Temperature |
| Equilibrium constant | K=Products/Reactants, only counting those in aqueos or gaseous form. Changes with T only. |
| 2 things to do when adding a substance to an equilibrium | 1. See if it forms a precipitate (ie. decrease conc of something). 2. Determine if it increases the conc of something. If a solid then make sure it is soluble. |
| Water to equilibrium | Decreases the conc. of all aqueos solutions (s and l not affected) |
| Pressure in Equilibrium | Solids not affected by it, system favours the side with the most number of moles |
| Learn | GRAPHS! |
