TOPIC 8 – KINETICS AND EQUILIBRIUM DO NOW: M.C. QUESTIONS IN PACKET ON KINETCS AND EQUILIBRIUM

TOPIC 8 – REGENTS REVIEW Temperature Concentration Nature of Reactants _Collision Theory states that a reaction is most likely to occur if reactant particles collide with proper energy and orientation The rate of a chemical reaction depends on several factors: Temperature Concentration Nature of Reactants Surface Area Presence of a Catalyst Pressure (gases only)

TOPIC 8 – REGENTS REVIEW Some chemical and physical changes can reach equilibrium At equilibrium the rate of the forward reaction equals the rate of reverse The measurable quantities of reactants and products remain constant at equilibrium Le Chateliers principle can be used to predict the effect of stress on a system in equilibrium Stressors include a change in pressure, volume, concentration, and temperature

TOPIC 8 – REGENTS REVIEW Energy absorbed or released by a chemical reaction can be represented by a potential energy diagram The amount of energy released or absorbed during a chemical reaction is the heat of reaction Heat of reaction = PE of product - PE of reactant Positive heat of reaction = endothermic-- Negative heat of reaction = exothermic

TOPIC 8 – REGENTS REVIEW A catalyst provides an alternate pathway for a chemical reaction. The catalyzed reaction required lower activation energy than the uncatalyzed reaction A solution Adding a catalyst increases the rate of the forward and reverse reactions equally so there is no shift in equilibrium

TOPIC 8 – REGENTS REVIEW Entropy is a measure of the randomness or disorder in a system. A system with greater disorder has greater entropy System in nature tend to undergo changes toward lower energy and higher entropy Exothermic reactions that result in increased entropy are spontaneous

TOPIC 8 – KINETICS AND EQUILIBRIUM SUMMARY ANSWER QUESTION IN PACKET