Chemis 3

• Thermochemistry


  Concerned with the heat changes that occur during chemical reactions
• Energy


  The capacity of doing work or supplying heat
• Heat (q)


  Energy that transfers from one object to another because of a temperature difference between them
• Endothermic Processes


  • The system gains heat as the surroundings cool down
• Exothermic Processes


  • The system loses heat as the surroundings heat up
• First Law of Thermodynamics

  Energy is neither created nor destroyed in any chemical or physical process
• Calorie


  The quantity of heat needed to raise the temperature of 1 g of pure water 1°C
• 1 Calorie


  Equals 4184 Joules
• 1 Calorie


  Equals 1 kilocalorie
• 1 Joule


  Equals 0.2390 Calories
• Heat Capacity


  The amount of heat needed to increase the temperature of an object exactly 1°C
• Specific Heat (C)


  The amount of heat it takes to raise the temperature of 1 gram of a substance 1°C
• Specific Heat (C)


  Equals heat (q) divided by mass (m) times change in temperature (ΔT)