About Me

My photo
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, July 1, 2011

To determine the energy value in food samples.

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 Bunsen burner and immediately placed under the boiling tube. 7. The flame from the cashew nut is allowed to heat up the water.
8. The water is stirred gently by using a thermometer to distribute the heat evenly. At the same time the rise in temperature is observed.
9. Measure and record the final temperature using the thermometer.
10. Precaution : Make sure that the nut is fully burnt and a shield is put around the nut to prevent heat loss to the surrounding.

No comments:

Post a Comment