Ch 7

• Calorimetry


  The measurement of heat energy changes in a reaction
• Calorimeter


  Device which measures heat changes in calories
• The change in temperature is used to measure the loss or gain of heat
• Exothermic reaction


  Heat released by reaction is absorbed by the surrounding solution
• Endothermic reaction


  Reactants absorb heat from the surrounding solution
• Specific heat


  The number of calories of heat needed to raise the temperature of 1 g of the substance
• Specific heat of water is 1.00
• To determine heat (Q) released or absorbed


  1. Know specific heat (SH_s)

  2. Know mass of the solution in grams (m_s)

  3. Know temperature change, final - initial (ΔT_s)
• Reaction is exothermic


  Heat was released to the surrounding solution
• Nutritional Calorie (Cal) = 1 kilocalorie (1kcal) = 1000 calories
• Bomb calorimeter is used to measure nutritional Cal