CALA COMPONENT E
DISTRICT :CHITUNGWIZA
SCHOOL : ZENGEZA 2 HIGH SCHOOL
LEARNING AREA :COMBINED SCIENCE
LEVEL :O' LEVEL
CALA TITLE : Testing for pH on local fruits and drinks consumed by learners at
Zengeza 2 High School
CALA TOPIC : Acids ,base and salts 8.7.3 pg 62
CONCEPTS / SKILLS
Collect
Research
Design
Practical skills
Data presentation
DIMENSION / CRITERIA
Learners will be assessed by the ability to :
1. Collect citrus fruits and drinks consumed by learners
2. Design an experiment
3. Carry out an experiment
4. Collecting and tabulating data
5. Suggest possible way of solving the problem
Assessment Objectives
8.3.2.7 Make logical decisions based on the examination of evidence and arguments
8.3.2.8 Apply scientific principles, formulae and method to solve qualitative and quantitative
problems.
Background
Learners and the community of Zengeza are suffering from stomach pains and tooth
aches ,which could have been caused by high level of acidity due to excessive consumption of
citrus fruits and carbonated acidic drinks.
Information guiding the learner
• pH level is identified by a specific colour change
• Tabulate your findings
• Correct and neat write up
• Accurate measurements
CALA ACTIVITIES
1. Collect citrus fruits and drinks consumed by learners at break time and lunch (5)
2. Design an experiment to identify pH in fruits and drinks samples (5)
3. Conduct an experiment to identify pH in fruits and drinks samples (10)
4. Present your results
5. Draw up conclusion and suggest ways to solve the problem (5)
MARKING GUIDE
1. Collect drinks and citrus fruits consumed
1 mark per each sample
2. Design an experiment
Aim (1 mark each)
Material (1 mark)
Method (2 marks)
Results (1/2 mark)
Conclusion (1/2 mark)
3. Conduct an experiment
Follow instructions (1)
Assemble apparatus (2)
Extraction of equal volumes (1)
Using the universal indicator correctly (1)
Match the colour (1)
Observe colour change (1)
Record results (1)
Team work (1)
4. Present results
Presentation (1/2)
Table (2)
Title (1)
Rows and columns (1)
Neat (1/2)
5. Conclusion
Well interpreted (2)
Solutions (3)
