Unit 2 ~ Energy and Rate of Reactions

thermochemistry

study of energy changes involved in a chemical reaction

Work

when a force is appiled that causes an object to move

Energy

the ability to do work

what are the 2 types of energy?

Potential and kinetic energy

Potential Energy

stored energy due to position or composition

Kinetic Energy

Energy of motion

Temperature

average kinetic energy of particles in a substance

Thermal Energy

total potential and kinetic energy particles in a substance

Heat (q)

transfer of TE from a warm object to a cool object

1st law of thermodynamics

Energy cannot be created or destroyed, because the total energy of the universe is constant

Chemical System

reactants and products being studied

Surroundings

everything other than the system being studied

Open system

both matter and energy can eneter and leave the system

Closed system

only energy can enter and leave the system

Isolated system

ideal system where energy and matter can’t enter or leave the system

Endothermic reaction

net release of energy ~ system gains energy

Exothermic reaction

Net absorption of energy ~ System loses energy

Chemical Kinetics

study of rate of reaction, look at affect and how reactions occur

Collision Theory

used to explain chemical reactions in terms of effective collision

what are 2 things needed for an effective collision

1. particles must have proper orientation

2. articles need enough kinetic energy

Activation energy

minimum amount of energy reactant molecules need for a reaction to be successful

Activated complex

intermediate molecules occurs when reactants are rearranging to form products