2.  Energy – the ability to do work or produce heat ◦ Kinetic energy – energy of motion ◦ Potential energy – stored energy  Chemical potential energy – stored energy because of composition

3.  Heat – energy process of flowing from a warmer object to a cooler object ◦ Calorie – the amount of heat required to raise the temperature one degree Celsius ◦ Joule – SI unit of heat and energy

4.  When your body breaks down sugars and fats to form carbon dioxide and water, these exothermic reactions generate heat that can be measured in Calories

5.  Specific heat – amount of heat required to raise the temperature of one gram of that substance by one degree Celsius  Units - J/g ⁰ C  Large specific heats = Large amount of energy to change temperature (water)  Small specific heats = Small amounts of energy to change temperature (gold)

6. q = m x c x ∆T q = mc∆T q (heat) c (specific heat) m (mass of sample) ∆T (change in temperature)

7.  The temperature of a sample of iron with a mass of 10.0g changed from 50.4 ⁰ C to 25.0 ⁰ C with the release of 114J heat. What is the specific heat of iron?  q = mc∆T  Heat (q) ◦ 114J  Mass (m) ◦ 10.0g  Specific Heat (c) ◦X◦X  Change in temperature (∆T) ◦ 50.4 ⁰ C - 25.0 ⁰ C = 25.4 ⁰ C  114 = 10.0(x)25.4  114 = 254(x)  X=.44881  Final answer 0.449J/g ⁰ C (3 significant figures and units)

8.  Calorimeter – insulated device used for measuring the amount of heat absorbed or released during a chemical or physical process

9.  Thermochemistry is the study of heat changes that accompany chemical reactions and phase changes

10.  Enthalpy (H) is the heat content of a system at constant pressure  Enthalpy of reaction ◦ ∆H rxn =H products – H reactants

11.  Endothermic = absorbs heat giving the ∆H rxn a positive number  Exothermic = releases heat giving the ∆H rxn a negative number