Title: SPECIFIC HEAT AND CALORIMETRYBACKGROUND: Calorimetry Method used to measure heat The accurate and precise measurement of heat change for chemical and physical processes. Calorimeter An insulated device used to measure the absorption or release of heat in a chemical or physical change. Usually water is the chemical that captures heat. Heat of combustion Combustion reactions are reactions of hydrocarbons (CHO) with oxygen. Types of chemical reactions: 1. Exothermic reactions In exothermic reactions the heat is released by the system (example: spark, flame or explosion). Combustion reactions are always exothermic. 2. Endothermic reactions Is a type of reaction in which the system absorbs heat from the surroundings, causing its surroundings to loose heat or “cool down”.
Specific heat, SH (J/g-oC) or (J/g-K) Heat needed to raise 1 g of substance 1oC. Capacity to gain (or lose) heat Also called heat capacity and specific heat capacity. Specific heat of water: 4.187 J/g-oC Heat or Energy (Q) Measured in Joules (J) or Calories (cal) A calorie is the amount of energy (heat) needed to raise the temperature of 1 g of water 1oC.Example:Determine the specific heat of 259 grams of copper at initial temperature of 22.3 deg C placed in374 grams of water with initial temperature of 92.7 deg C. The final temperature after putting thecopper in the water is 88.5 deg C.Solution: = - 6,576.9396 J Substituting; C = 0.3836 J/g-KReference:Washington State Community College