Student Example- PowerPoint
- 1. Thermochemistry Heat Of Reaction Lab By: Meredith Dillon Partners: Stephen Dawson and Mollie Safran
- 2. Purpose and Procedure Purpose: Determine the heat of combustion for paraffin Heat of Combustion: Amount of Heat Released when one mole of a substance combusts Procedure 1. Set Up Apparatus 2. Heat water from 10 ºC to 35ºC. Record temperatures with thermometer. 3. Record Mass of Candle and Lid
- 3. Data, Results, and Conclusions Thermochemical Equation: C 25 H 52 + 38 O 2 25 CO 2 + 26 H 2 O + 8,607.95 KJ 140.5 Mass Water (g) 24.04 Final Mass Candle and Lid (g) 35.5 Final Temperature of Water (g) 9.7 Initial Temperature of Water (g) 24.66 Initial Mass Candle and Lid (g) Lab Data 8,607.95 ∆ H (KJ/mol) 1.76x10 -3 Moles Wax 352 Molar Mass Wax (g) .62 Mass Wax (g) 15.15 Heat Released By Was (KJ) 25.8 ∆ T H 2 0 ( ºC) Calculations
- 4. Data, Results, and Conclusions (Cont.) Reaction Coordinate (Exothermic Reaction) If 10.0 grams of wax combusts… Reactants Products E A ∆ H (8,607.95 KJ/mol)
- 5. Lab Error Actual Molar Heat of Combustion for Paraffin= 14,800 KJ/mol Lab Result for Molar Heat of Combustion for Paraffin= 8,607.95 KJ/mol The actual heat of combustion is much bigger than we tested in lab. This could have been because the heat in the reaction was being transferred out of the surroundings of the reaction (water) and into the universe (air, container, etc).