Learning Goal for Today Energy Test Review Learning Goal for Today I will be able to interpret potential energy diagrams for reactions, determine if a reaction is endothermic or exothermic and define open, closed and isolated systems.

Potential Energy Diagrams b a c d Answer the following questions by looking at the above diagram. Which letter represents the product? Which letter represents the change in energy? Which letter represents the activation energy? d c b

Potential Energy Diagrams 1. What is the activation energy in the above diagram? a. 50kJ b. 250 kJ c. 200 kJ d. 150 kJ 2. What is the correct change in energy in the above diagram? a. 150 kJ released c. 50 kJ released b. 150 kJ absorbed d. 50 kJ absorbed c. 200 kJ d. 50 kJ absorbed

b. melting, sublimation and vaporization Phase Diagram Which phase changes will have an increase in energy? a. condensation, deposition and freezing b. melting, sublimation and vaporization c. condensation, freezing and sublimation d. deposition, melting and vaporization b. melting, sublimation and vaporization

Types of Systems Isolated systems: They do not exchange heat, work or matter with their environment. Closed systems: are able to exchange energy (heat and work) but not matter with their environment. Open systems: exchange energy (heat and work) and matter with their environment.

Identify which system would be described in each of the graphics open closed isolated   Identify which system would be described by each of the items or concepts that follow: A cold pack The universe Using a flashlight Eating a turkey dinner A glow stick A hand warmer Lighting a candle closed isolated closed open closed open open

Factors Affecting the Rate of Reaction Temperature: Raising the temperature speeds up reactions, while lowering the temperature slows down reactions. Concentration:Cramming more particles into a fixed volume increases the concentration of reactants and consequently the frequency of collision.

Factors Affecting the Rate of Reaction Particle Size:The smaller the particle size, the larger is the surface area for a given mass of particles. An increase in surface area increases the amount of the reactant exposed for reaction, which further increases the collision frequency and the reaction rate. Catalysts:a substance that increases the rate of a reaction without being used up during the reaction.