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K & E
Regents Chem - Kinetics & Equilibrium
Question | Answer |
---|---|
Activation energy | energy required to take reactants or products to the top of a potential energy diagram. Every reaction has activation energy |
Spontaneous reaction | process that occurs on its own, without outside involvement. Usually exothermic (negative delta H) and increase in entropy (positive delta S) |
Chemical Equilibrium | rates of forward and reverse reactions are equal. Concentrations are constant. |
Solution equilibrium | in a saturated solution when rate of dissolving equals rate of crystallization |
Phase equilibrium | in a closed container, rate of evaporation equals rate of condensation. If container is NOT closed, the gas will just escape. |
LeChatlier’s Principle | when a stress is placed on a system at equilibrium, one direction will be favored so that the stress can be alleviated. |
Keq | Equilibrium constant expression. Concentration of products divided by concentration of reactants. Coefficients become exponenets |
Effect on equilibrium of increasing reactant concentration | shift to product side. More products are made but reactants decrease. |
Effect on equilibrium of adding a catalyst | a catalyst has NO EFFECT on EQUILIBRIUM! |
Effect on equilibrium of increasing temperature | shift away from the heat (kJ). The shift is in the endothermic direction |
Effect on equilibrium of decreasing temperature | shift to the side with the heat…this will raise the temperature back up. |
Effect on equilibrium of increase in pressure | shift to the side with less moles. Less stuff can fit better in a smaller container. |
Enthalpy | heat content of a system |
Entropy | measure of the disorder or chaos of a system |
Effect of a catalyst on collisions and reaction rate | provides another mechanism for the reaction with less activation energy so more collisions are effective |
Effect of increased surface area or increased temperature on collisions and reaction rate | more collisions, more effective collisions, increased rate (it takes less time) |
2 factors needed in order for collisions to be effective | proper kinetic energy and proper orientation |