Wednesday, 7 December 2011

Science Year 5 - Acid and alkaline

Subject             : Science  ( Year 5 )
Date                 : 25.10.2011 (Tuesday)
Time                : 10 : 00 – 10 : 30 (30 min)
Standard           : 5S
Enrolment        : 41 pupils
Topic                : Acid and alkaline
Sub-topic          : 2.1 Understanding the properties of acidic , alkaline and neutral substances
Learning Outcomes : By the end of the lesson, pupils will be able to
a)      Identify acidic, alkaline and neutral substances using litmus paper.
b)      Identify the taste of acidic and alkaline food.
Previous knowledge : Pupils have learnt about
a)      The tastes of food substances and colour.
b)      Mixing vinegar with baking powder in Year 3.
Thinking skills : Making hypothesis, generating ideas, making conclusions
Moral values : Being cooperate, being respect
Teaching and learning resources : Litmus paper, lemon, tooth paste, soap, cooking oil, vinegar, canned drink, shampoo, sugar, salt, yogurt



(5 min)

To predict the taste of substances.

1  Teacher ask pupil about the taste of lemon.
Answer :The taste is sour.
2. Teacher explain that substances can be classified  as acidic, alkaline and neutral.
3. Teacher as people to observe the the colour change of the wet red and blue litmus paper after put on the lemon.
Observation: The red colour of litmus paper no changes colour, but the blue colour of litmus paper changes to red colour.
4. Teacher asks pupils to carry out hands-on activity to the experiment.

Red and blue colour of  litmus paper

Thinking Skill : predict

Step 1
(10 min)

Step 2
(5 min)

To observe the change colour of blue and red litmus paper.

Group discussion to make :
a   Observation
b   Conclusion

1  Teacher asks pupil conduct an experiment in groups to observe the change colour of wet blue and red litmus paper .
2  Teacher provides each group blue and red colour litmus paper and :
Group A  lime, mineral water, shampoo, vinegar.

Group B canned drink, cooking oil, tooth paste, sugar.
Group C  yogurt, salt, shower jell, pineapple .
Group D  soap, liquid detergent, tomato, ketchup.
3  Teacher remind pupils when testing, the litmus paper must be wet, also not to taste the food before being advised to do so.
4  Pupils work in groups and record their finding on the change colour of blue and red litmus paper.

1   Teacher asks pupil to discuss in group to make hypothesis and conclusion.

2   Teacher goes around to observe pupils.

litmus paper, lime, mineral water, shampoo , vinegar, canned drink, cooking oil, tooth paste, sugar, yogurt, salt, shower jell, pineapple, soap, liquid detergent, tomato and ketchup.

Thinking Skill: to observe

Moral Value : Being cooperate

Thinking Skill : Observation and conclusion

Moral Value  : Being cooperate

Step 3


1  Teacher asks each group make presentation for group discussion.
2   Pupils respond :
Lime, vinegar, canned drink, pineapple, tomato :
changes blue litmus paper to red colour, but red litmus paper no changes the colour.
The taste : sour

Shampoo, tooth paste, liquid detergent , soap :
changes red litmus paper to blue colour, but blue litmus paper no changes the colour.
The taste : bitter

mineral water, sugar, yogurt, salt, ketchup :
No changes red and blue litmus paper colour.
The taste : neutral , sweet or sour

3  Teacher discuss the answer 
with pupils.

Moral Value : Being respect

(3 min)

1   Teacher give worksheet to each pupil.
2   Teacher goes around to observe pupils.

AVA : worksheet

 Remarks : Teacher  can play the information.

Name : 
 Class :

Topic : Acid and alkaline

1.      Lee Fong and Fatimah carried out an investigation on the properties of substances M, N and O.
They used blue and red litmus papers to investigate the properties of the substances. The table below shows the observations of the investigation.

The colour changes of litmus paper
Red litmus paper
Blue litmus paper
No change
No change
Change to blue
No change
No change
Change to red

(a)    State the thing that is kept the same.


(b)   Explain the colour changes of litmus paper on Substance N.


(c)    Based on the observations above, predict the taste of Substance M and N.
(i)  Substance M: ___________________________ 
(ii)  Substance O: __________________________

Underline the correct answers.

1.      ( Alkaline , Neutral ) substances are slippery to the touch and taste bitter.

2.      The pH value of neutral substances is ( 7 , 8 ) whereas acidic substances has the pH of ( 1-6 , 8-14 ).

3.      Strong acidic and alkaline substances are ( corrosive , tetanus ) and ( protest , burn ) our skin.

4.       ( Salt water , Soap ) does not change the colour of a litmus paper because it is ( neutral , acidic ).

5.      Substances that taste bitter are generally ( acidic , alkaline ).

1 comment:

  1. are u a science year 5 teacher? need some opinion from u regarding some of the topics in this particular subject..