8/12/2019 4a Ezperiment Manual

1/4

Section A: Conducting the experiment

Title: Nutrition

Learning Objective: In this unit, students carry out an experiment to determine the energy value in food

samples.

Materials and apparatus: Fresh ground nuts, white bread, matches, distilled water, plasticine, Boiling tube,

thermometer, long pin, electronic weighing machine, measuring cylinder

Instructions for students:

Method 1. One fresh ground nut was weighed and the mass was recorded.2. 1 boiling tube was filled with 20ml of distilled water.3. The apparatus of the experiment was set up as shown in the diagram.

4. The initial temperature, t1of the water was recorded.5. The ground nut was burned and put as near as possible to the bottom of the boiling tube.6. The water was stirred.7. The final temperature, t2 of the water was read and recorded when the ground nut has

stopped burning.

8. The energy value of the ground nut was calculated.

9. Steps 18 were repeated using white bread.Results

Food sample Ground nut White bread

Initial temperature of water (0C)

Final temperature of water (0C)

Difference in temperature (0C)

Mass of water (g)Mass of nut (g)

Energy value (Jg-1 0

C-1

)

8/12/2019 4a Ezperiment Manual

2/4

Section B: Writing Report

Based on your experiment, write a report that consists of the following subjects:

a. Aimb. Problem statementc. Hypothesisd. Variablese. Materials and apparatusf. Prosedurg. Tabulating datah. Data analysisi. ConclusionSection C: Answering Questions

Discuss the following questions based on your experiment results:

a. Observed that the results obtained was not accurate. State steps of precaution that can be taken to get moreaccurate results.

I. ____________________________________________________________________________________________________________________________________________________________________________

II. ____________________________________________________________________________________________________________________________________________________________________________

III. ____________________________________________________________________________________________________________________________________________________________________________

b.

The article above is retrieved from a newspaper. Based on the information in the article, discuss how parents

can help to educate their children to have a balanced eating habit since childhood.

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________

They do not recognisethat it (obesity) is a disease. So, no one cares and think it is okay to be fat. Once you

treat it as a disease, it will make people aware, he said.

He said obesity was the underlying factor for chronic diseases such as diabetes.

Obesity and being overweight are among the risk factors for type II and gestational diabetes which occurs

during pregnancy.

Malaysia is ranked sixth in the Asia-Pacific region for obesity and tops the list in South-East Asia for both

obesity and diabetes.

Deputy Health Minister Datuk Seri Dr Hilmi Yahaya recently said that there were about three million obese

Malaysians and the number was increasing while there were about five million individuals who suffer from

varying degrees of diabetes.

A sedentary lifestyle is among the main factors for the high incidence.

Dr Mohd Ismail said some parents thought having chubby children was a reflection that they were well-fed

and cared for but they did not realise that the child was likely to be overweight during puberty and this would

continue throughout their lifetime.

Bernama

8/12/2019 4a Ezperiment Manual

3/4

Section A: Conducting the experiment

Title: Nutrition

Learning Objective: In this unit, students carry out an experiment to determine the vitamin C content in

fruit juices.

Materials and apparatus: 0.1% ascorbic acid solution, DCPIP solution, lemon juice, pineapple juice and orange

juice, Specimen tubes, syringes, measuring cylinder

Instructions for students:

Method

1. Four specimen tubes were labeled as A, B, C and D.2. 1 ml of DCPIP solution was placed in each specimen tube using a syringe.3. A syringe was filled with 5ml of ascorbic acid solution.4. The needle of the syringe was immersed in DCPIP solution.5. The ascorbic acid solution was added drop by drop to the DCPIP solution and the tube was

shaken slowly.

6. The amount of ascorbic acid solution used to turn the DCPIP solution colorless was recorded.7. Steps 2-6 were repeated using lemon juice, pineapple juice and orange juice replacing the

ascorbic acid.

8. The percentage and concentration of vitamin C in the three types of juices were calculated.

Results

Solution Initial volume

(ml)

Final volume

(ml)

Volume used

(ml)

Percentage

of vitamin C

(%)

Concentratio

n of vitamin

C (mg cm-3

)

Ascorbic acid

Lemon juice

Pineapple juice

Orange juice

8/12/2019 4a Ezperiment Manual

4/4

Section B: Writing Report

Based on your experiment, write a report that consists of the following subjects:

a. Aimb. Problem statementc. Hypothesisd. Variablese. Materials and apparatusf. Prosedurg. Tabulating datah. Data analysisi. Conclusion

Section C: Answering Questions

Discuss the following questions based on your experiment results:

a. What reaction causes the DCPIP solution to change color?___________________________________________________________________________________________

___________________________________________________________________________________________

b. When the ascorbic acid solution or the fruit juice is added to the DCPIP solution, the tube containing thesolution cannot be shaken vigorously. Why is this so?

___________________________________________________________________________________________

___________________________________________________________________________________________

c. Predict the results obtained if the fruit juice is prepared a day before the experiment.___________________________________________________________________________________________

___________________________________________________________________________________________

d. What is the relationship between the content of the vitamin C in fruit juice with the volume of fruit juicerequired to turn the DCPIP solution colorless?

___________________________________________________________________________________________

___________________________________________________________________________________________