Lesson Plan
Lesson: Redox Potential
Aim :
To study the redox potentials of electrochemical cells.
Learning Outcomes :
By the end of the lesson, students will be able to:
• explain the use of standard hydrogen electrode as a reference electrode in
the determination of standard electrode potentials of other half-cells.
• use the standard electrode potential series to compare the oxidising and
reducing agents.
• use the electrochemical series to compare the reactivity of metals.
Assumed prior knowledge :
Students should already be familiar with :
1. the concept of electrode potential of a half-cell.
2. the terms; oxidation, reduction, reducing agent, oxidising agent, reactivity of metals.
Underlying Principles
1. Making the invisible, visible.
2. Enabling students to know what to look for.
Time taken to complete the activities : 80 minutes
Differentiation
Questions in the student notes are designed to enable all students to complete the activity.
The pop-up answers are provided for the students to view when they have considered their
responses. Worksheet questions include questions that require recall, understanding and
application of the new concepts learned.
© 2003 Ministry of Education Malaysia. All Rights Reserved. Page 1 of 3
Development of Lesson :
No. Steps Strategy Resources
1 Set Induction. • Teacher to quiz students to ensure that
(Ascertaining prior they have the necessary background
knowledge and knowledge.
introducing lesson
topic for the day). • Teacher to point out lesson objectives for
the day.
2 Student Activity Teacher to go through Activities 1 - 2 • Courseware
with the students.
• Activity 1 : Standard electrode
potentials
Students are shown how the standard
electrode potential of a half-cell is
measured by using the standard
hydrogen electrode as a reference
electrode.
• Activity 2 : Standard electrode
potential series
Students are shown how the electrode
potential series is obtained. They are also
shown how to determine the relative
strength of oxidising and reducing agents
from their position in the electrode
potential series.
3 Evaluation • Students to answer questions in the • Worksheet
student worksheet on their own.
4 Extension activity • Students to go through the extension • Websites
activities on their own. • Reference
books.
© 2003 Ministry of Education Malaysia. All Rights Reserved. Page 2 of 3
Worksheet answers
1. Standard electrode potential
1.1 a. The standard electrode potential of silver refers to the potential difference
between the standard hydrogen electrode and the silver electrode measured
under standard conditions.
b. A - 1 mol dm-3 H+(aq)
B - Platinum
C - H2(g)
D - Voltmeter
E - Salt bridge
F - Silver electrode
G- 1 mol dm-3 Ag+(aq)
c. i. silver electrode
ii. hydrogen electrode
iii. hydrogen electrode
d. H2(g) + 2Ag+(aq) 2H+(aq) + 2Ag.
1.2 a. A - Platinum
B - Solution containing 1 mol dm-3 Fe3+(aq) and
1 mol dm-3 Fe2+(aq).
C - Salt bridge
D - Platinum
b. Change in any two of these conditions:
temperature, pressure, concentration of solution.
c. i. The standard hydrogen electrode - negative pole
Fe3+/Fe2+ electrode - positive pole.
ii. From the standard hydrogen electrode to the Fe3+/Fe2+ electrode.
2. Standard Electrode Potential Series
2.1 a. Cl2
b. Mg2+ < Br2 < Cl2
2.2 a. Ca < Zn < Fe
b. Fe < Zn < Ca
© 2003 Ministry of Education Malaysia. All Rights Reserved. Page 3 of 3
