Science - Teachers Sri Lanka

Competency 3.0 : Use chemical change suitable to fulfil necessity of life
Competency
Level 3.5 : Control the rate of chemical reaction
Activity 3.5 : Let us investigate about the factors affecting the rate of
chemical reaction.
Time : 210 mts.
Copyright © 2007 National Institute of Education - Sri Lanka. All rights reserved.
Quality Inputs : • Spakle, Sandalwood stic and a box of matches
• Four copies of the two page artical on instructions for
exploration given in annex 3.5.1
• Four work station arranged according to instrution given
in annex 3.5.2
• Demy papers and pastels
Teaching Learning Process
Step 3.5.1 • Ignit the Sparkle, Sandalwood stic at the same time and
direct the students to observe.
• Discuss about the students observations.
• Lead a discussion highlighting the following points.
• When Sparkle and Sandalwood stic were ignited the
chemicals present in them burn.
• The rate of burning of Spakle is greater than the rate of
burning of Sandalwood stic.
• There are different factors which could affect the rate
of a reaction.
• The rate of a chemical reaction could be decided by the
time taken to decrease a certain quantity of reactants or
the production of a certain quantity of the product.
(15 mts.)
Step 3.5.2 : • Divide the class into four groups.
• Provide the group with instrutions for exploration, demy
pastels.
• Assign the tasks and engage the groups in exploration.
• Prepare them to present their findings to the class.
(60 mts. )