1. Ch 10 - Energy

2. KE = ½ mv2 The Nature of Energy
Energy is the ability to do work or produce heat/light.
Potential Energy is energy due to position
Kinetic Energy is energy due to motion (depends upon mass and velocity)
KE = ½ mv2

3. Temperature vs Heat
Temperature is the measure of the average kinetic energy in a system. (measure the motion of the particles)
Heat is the sum of the particle kinetic energy in a system.
Temperature and heat are NOT how hot or cold something is…….they are measuring energy in a system……

4. Thermodynamics Exothermic and Endothermic Reactions
Exothermic reaction occurs when energy flows out of a system into the surroundings. (feels hot to the touch)
Endothermic reaction occurs when energy flows from the surroundings into a system. (feels cold to the touch)

6. Measuring Energy Changes
The amount of energy gained or lost during a chemical reaction can be calculated:
q = (mass)(change in Temperature)(Specific heat)
q = m∆TCp
q is measured in Joules or kilojoules and is the amount of energy lost or gained
m is mass, measured in grams
Change in temperature (∆T) is final temp – initial temp
Specific heat (Cp) is a constant. It is the amount of energy needed to raise the temp of 1 g of a substance 1oC

7. First Law of Thermodynamics
Also called …….. Law of Conservation of Energy Energy can not be created or destroyed, it can only change form….. q lost = q gained Energy lost must be absorbed (or gained)