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Thermochemistry Thermochemistry Notes1. Thermochemistry-

HeatStudy of energies in chemical reactions

Thermochemistry2. Heat Flow: Heat always flows

from hot to cold Ex: A refrigerator works by

removing heat not adding cold

Thermochemistry3. Law of conservation of energy: energy is not

created or destroyed, it is just transformed Ex: Sun provides energy to grow apple

You eat the apple Your body breaks down the apple to make energy You use the energy to water the apple tree …

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Thermochemistry4. Units of Energy: Joules (J), calories (cal), Calories (Cal) Food Calories

1 cal = 4.184 J 1 Cal = 1000 cal 1 kJ = 1000 J1 kcal = 1000 cal

Thermochemistry5. Ex: Convert 8.5 J to calories

1 cal = 4.184 J1 Cal = 1000 cal

1 kJ = 1000 J

8.5 J4.184 J

1 cal = 2.0 calx

Thermochemistry6. Ex: Convert 4.50 kJ to calories

1 cal = 4.184 J1 Cal = 1000 cal

1 kJ = 1000 J

4.50 kJ1 kJ1000 J = 1,075.52 calx

4.184 J1 calx = 1,080 cal