You should tie back any loose objects such as hair or ties as these may get dangled in the flame and burn. .
Fair test.
There are plenty of precautions I can take to make sure this is a fair test.
I should make sure that the glass is not still cooling down from the last experiment and that both the water and the glass are the same temperature each time.
I should always use the same water i.e. always use tap water.
I should always keep the Bunsen burner and the beaker in the center of the tripod and gauze.
Method.
*Gather up all apparatus and set it up according to the diagram below. .
*Light the Bunsen burner but do not put it under the gauze until later. Get the stopwatch ready to time before the experiment, as you will start timing as soon as you put the Bunsen burner under the gauze.
*Start with the air hole closed all the way and keep the gas top on fully. You will only have the gas tap closed for this experiment, as it will differ for later experiments. After the experiment do it exactly the same again to confirm your results are right. Take the water temperature before you start heating and decide on the temperature increase. Keep this increase you have chosen throughout the experiments. .
*Heat the water by placing the Bunsen burner underneath the gauze. The beaker full of water should be placed in the centre of the gauze. As soon as the Bunsen is placed under the gauze you should start timing. Keep looking at the thermometer in the beaker to check the temperature. Stir the water whilst you are keeping time. Once the water as risen to the desired temperature you chose, stop the timing and take the Bunsen out from under the gauze. Record results and repeat the experiment once more. Again record the results. Remember that for these two experiments the air hole must be closed all the time. .
*Restart the experiment just like before but this time, open the hole 1mm. Record the results and do the same experiment again.