Method

This is for a neutralisation reaction adding increasing volumes of alkali to the acid

  • Using a measuring cylinder measure 30cm of dilute acid and pour into a polystyrene cup
  • Then stand he cup inside a beaker
  • Use a thermometer to measure temperature of acid
  • Measure 5cm of alkali into cup with a measuring cylinder
  • Then add a plastic lid on the cup to prevent unwanted energy transfers
  • Place a thermometer through the lid making sure the bulb is in the solution
  • Gently stir with thermometer
  • When reading on thermometer stops increasing record the maximum temperature it reached
  • Repeat with increasing volumes of alkali until you reach 40cm
  • Repeat the whole experiment to obtain another set of results and calculate the mean value of maximum temperature reached for each volume of alkali
  • Then plot a graph of results

Results

The temperature will increase proportionally to the volume of alkali added until it reaches a maximum when everything reacts. Then adding more alkali decreases the temperature as no more energy is released but it is spread out over a large volume