|2005 |2006 |2007 |2008 | |( (1) | |( (1) | |
1 An experiment was carried out to determine and compare the energy content in white bread and peanuts. The mass of each food sample used was 5g.
The volume of distilled water used was 20 ml.
The density of water is 1 gm/-1
Figure 1 shows the set-up of the apparatus used in the experiment
Figure 2 shows the initial water temperature for each food sample.
Table 1 shows the highest water temperature after each food sample is completely burnt.
(a) (i) Record the initial water temperature in the space provided in Figure 2.
(ii) Record the final water temperature in the boxes provided in Table 1. [3 marks]
(b) (i) State two different observations made from Table 1.
1 The temperature of water after burning white bread is 34˚ C.
2 The temperature of water after burning peanut is 50˚C [3 marks]
(ii) State two inferences from the observations in (b)(i). 1 White bread burnt and releases low heat energy.
2 Peanut burnt and releases high heat energy
(c) Complete Table 2 based on the experiment that was carried out.
|Variables |Particulars to be implemented | |Manipulated variable |How to alter the manipulated variable | |Food sample/white bread and peanut |Use different food sample i.e white bread and peanut | | | | |Responding variable |How to determine the responding variable | |Temperature changes/energy value of food sample |Measure and record the increase in temperature of water by using a | | |thermometer. | | |Calculate the energy value using the given formula | |Controlled variable |How to maintain the controlled variable | |Mass of food sample. |Use the same mass of each sample food | |Air movement and temperature surrounding the experiment |Ensure air movement and temperature surrounding the experiment is the | | |same. |
(d) State the hypothesis for this experiment.
The rise in temperature for peanut is higher than whitebread./ The energy value for the peanut is higher than the whitebread. [3 marks]