17. Candle Flame Energy Scientific Enquiry Lessons

Jasminder wanted to investigate the heating of water using a candle. She wrote “ I predict that the rise in temperature would depend on the volume of water in the beaker”. The diagram shows how she set up the apparatus.

Jasminder recorded her results in a table as shown below. (a)Why did Jasminder need to know the temperature of the water at the beginning and at the end of the experiment? __________________________________________ _________________________________________________ beakervolume of water, in cm 3 temperature at start, in °C temperature after2 minutes, in °C A B C751923

(b) Did her results support her prediction? If YES, explain why they did. If NO, say why not. ______________________________________ (c) Jasminder stirred the water during the experiment. How did this make the results more reliable? ______________________________________

(d). (i). What temperature rise result would you expect if Jasminder used a fourth beaker D containing 100 cm 3 of water ?___________________________________ (ii).Is it essential that she always started with water at the same temperature? (19 °C). Give a reason ___________________________________

(e). Look at the apparatus diagram again. THINK! (i). At one time someone opened the window near to the experiment. Sometimes the candle flickered as other pupils passed by. Suggest how Jasminder could set up her practical work to reduce these problems. ______________________________________

(ii). Other pupils decided to use a new piece of candle for each part of their experiment. Jasminder thought that was not fair and would spoil the results. She wanted the same candle for every beaker. Evaluate the two different methods. Pick out the good points of each way of doing things (if there are any!) Point out problems of both methods. ______________________________ ______________________________________ ______________________________________ ______________________________________ ______________________________________

(iii).If the same candle is used for the experiment, think how the results might be affected and so how strong is the evidence to support Jasminder’s original prediction? ______________________________________