Thermochemistry

Temperature

• Temperature: the measure of the average kinetic energy of atoms or molecules
• The more kinetic energy, the faster the molecules move, and the higher the temperature

Endothermic Reaction

• heat is absorbed
• +q or +(delta)
• on the reactant side
• feels cold
• products higher than reactants

Exothermic Reaction

• heat is released
• -q or -(delta) H
• heat is a product
• feels warm/hot
• products lower than reactants

Heat Calculations

• q=mC(delta)T
• q= heat in calories or Joules
• m= mass in grams
• C=specific heat
• (Delta)T= change in temperature

Units of Heat

• calorie: energy needed to raise 1g of water 1 degree celsius
• Calorie: equal to a food calorie
• 1 Cal=1000 cal=1Kcal
• Joule: 1 cal= 4.184J
• 1KJ=1000