4.11 describe simple calorimetry experiments for reactions such as combustion, displacement, dissolving and neutralisation in which heat energy changes can be calculated from measured temperature changes

4.11 •you can find out enthalpy changes using calorimetry 

        •for dissolving, displacement and neutralisation reactions

                  •to measure the amount of energy transferred, you take the temperature of the regents (making sure they’re the same), mix them and then measure the temperature of the solution at the end of the reaction 

        •mix the reactants in a polystyrene cup, all in a beaker with cotton wool to give more insulation and a lid on the cup to reduce energy lost by evaporation, so the experiment is more accurate  

         •for combustion reactions 

                   •to measure the amount of energy of fuel burnt, you burn the fuel and use the flame to heat up some water

        1. reducing draughts is key to make sure as much heat as possible goes to heating up the water. Use a screen to act as a draught excluder 

        2. put 50g of water in the copper can and record it’s temperature 

        3. weight the spirit burner and lid

        4. heat the water an stir constantly, until the temperature reaches 50 degrees

        5. put out the flame and measure the final temperature of the water

        6. weigh the spirit burner and lid again 

                  •you can now use the measurements to calculate the enthalpy change