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My name is Poon Cheng Moh. I have been teaching biology in SMK(P) Raja Zarina, Port Klang for 26 years. I sincerely hope that this blog on SPM Biology will be useful to both teachers and students.

Friday, June 17, 2011

To determine the energy value in food samples.


To determine the energy value in food samples.

Problem statement

What is the energy value in cashew nut and groundnuts?


Cashews nuts have higher energy value than ground nuts.


Manipulated : Types of food sample: Cashew nut and ground nut

Responding : The rise in temperature of water//Energy value

Constant : Volume of distilled water

Apparatus and materials

Apparatus (A): Boiling tubes, retort stand, plasticine, long pins, thermometer, electronic weighing scale, 25ml measuring cylinder

Materials (M) :Fresh ground nuts, fresh cashews nuts, distilled water and matches


Measure and record the rise in temperature by using a thermometer//

Calculate the energy value using the formula:

Energy value = 4.2 (Jg-1 oC-1) x mass of water (g) x increase in temperature(oC)/Mass of peanut(g)


  1. Weigh the cashew nut and record its weight.
  2. Fill a boiling tube with 20ml of distilled water.
  3. Clamped the boiling tube to a retort stand.
  4. Record the initial temperature of the distilled water.
  5. The pointed end of a long pin is poked into the cashew nut. The other end of the pin is poked into with a piece of plasticine.
  6. The cashew nut is ignited by using a match stick and immediately placed under the boiling tube.
  7. The flame from the cashew nut is allowed to heat up the water. The water is stirred gently by using a thermometer to distribute the heat evenly. At the same time the rise in temperature is observed. Measure and record the final temperature using the thermometer.
  8. Record the final temperature of the water in a table.
  9. The energy value of the cashew nut is calculated using the formula :

Energy value = 4.2 (Jg-1 oC-1) x mass of water (g) x increase in temperature (oC)/ Mass of peanut(g)

10. Steps 1 to 9 are repeated by using a groundnut.

11. Precaution : a) Make sure that the nut is fully burnt.

b) A shield is put around the nut to prevent heat loss to the surrounding.

Recording data/ result

Food sample

Cashew nut



Initial temperature of water (oC)

Final temperature of water (oC)

Rise in temperature (oC)

Energy value (J)


Cashew nut has a higher energy value than groundnut. The hypothesis is accepted.

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