SCHEME OF ORK
WEEK TOPIC
1 Revision/ Periodic table - Electronic configuration leading to group and periodic classification.
2 - 3 -The Periodic trend: The periodic properties of elements i.e Atomic size, ionic size, and ionization energy, electron affinity, electronegativity down the group & across the period.
- Elements of the first transition series.
4-5 Oxidation & Reduction (Redox reactions)
i. The use of oxidation no.
ii. Balancing of Redox equations in acidic & basic medium.
iii. Identification of oxidizing & reducing agents.
6 -7 ELECTROLYSIS
i. Effects of electricity on matter.
ii. Electrolytes & non -electrolytes.
iii. Conductors & non - conductors.
iv. Ionic theory.
v. Preferential discharge of ions during electrolysis.
vi. Electrolysis of specified electrolytes.
8 - 9 Faraday's law of Electrolysis
i. Faraday as a mole of electrons.
ii. Calculations based on these laws.
iii. Uses of Electrolysis e.g. Electroplating E.t.c.
10 Electro - chemistry
Electrolyte for Electrochemical cells with their differences.
The relationship between Gibbs free energy & E.M.F of a cell.
11 Revision.
1ST TERM
WEEK 1
TOPIC: THE PERIODIC TABLE
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Recall important contributors to the development of the periodic table.
2. Classify the periodic table into periods and groups.
3. Define the periodic table.
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; ESSENTIAL CHEMISTRY by O. ODESINA
CONTENT: ELEMENT
The periodic table started long time ago 330Bc when Aristotle described three element theory earth, air and water. Antoine Lavoisier compiled the first lost of 33 element distinguished between metal and non metals. Berzelius Mendeleev, William Ramsey and Henry Mosley all contributed to achieve the present periodic table.
The periodic table arranged elements in a regular pattern according to their increasing atomic number.
EVALUATION:
Describe the basis of the position of elements in the periodic table.
ASSIGNMENT:
State the periodic law.
SUB TOPIC: GROUPS AND PERIODS OF THE PERIODIC TABLE
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Describe the group and period of the periodic table.
2. State the common properties of elements in the same group and same period.
CONTENT: ELEMENT
The vertical columns of elements are referred to as groups. The groups are numbered from 0 to 7. Elements in the same group have the same number of electrons in their valence shells.
The horizontal rows of elements are referred to as periods. There are 7 rows (periods). Elements in the same period have the same number of electron shells.
EVALUATION:
Consider the following elements:
3Li, 11Na, 17CL, 13Ai, 8O, 10Ne, 12Mg, 14Si.
1. Put them into their respective groups and periods.
2. Classify them into metals, metalloids and non metals.
SUB TOPIC: ELECTRONIC CONFIGURATION AND PERIODIC TABLE
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Recall the concept of electronic configuration.
2. Classify elements into S, P, D and F blocks based on their electronic configuration.
3. Identify the transition elements, the lanthanides and the actinides.
EVALUATION:
Explain briefly, in terms of electronic configuration, the occurrence of periods, groups and transition series in the periodic table.
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Recall important contributors to the development of the periodic table.
2. Classify the periodic table into periods and groups.
3. Define the periodic table.
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; ESSENTIAL CHEMISTRY by O. ODESINA
CONTENT: ELEMENT
The periodic table started long time ago 330Bc when Aristotle described three element theory earth, air and water. Antoine Lavoisier compiled the first lost of 33 element distinguished between metal and non metals. Berzelius Mendeleev, William Ramsey and Henry Mosley all contributed to achieve the present periodic table.
The periodic table arranged elements in a regular pattern according to their increasing atomic number.
EVALUATION:
Describe the basis of the position of elements in the periodic table.
ASSIGNMENT:
State the periodic law.
SUB TOPIC: GROUPS AND PERIODS OF THE PERIODIC TABLE
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Describe the group and period of the periodic table.
2. State the common properties of elements in the same group and same period.
CONTENT: ELEMENT
The vertical columns of elements are referred to as groups. The groups are numbered from 0 to 7. Elements in the same group have the same number of electrons in their valence shells.
The horizontal rows of elements are referred to as periods. There are 7 rows (periods). Elements in the same period have the same number of electron shells.
EVALUATION:
Consider the following elements:
3Li, 11Na, 17CL, 13Ai, 8O, 10Ne, 12Mg, 14Si.
1. Put them into their respective groups and periods.
2. Classify them into metals, metalloids and non metals.
SUB TOPIC: ELECTRONIC CONFIGURATION AND PERIODIC TABLE
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Recall the concept of electronic configuration.
2. Classify elements into S, P, D and F blocks based on their electronic configuration.
3. Identify the transition elements, the lanthanides and the actinides.
EVALUATION:
Explain briefly, in terms of electronic configuration, the occurrence of periods, groups and transition series in the periodic table.
WEEK 2
TOPIC: TRENDS IN THE PERIODIC TABLE
SUB-TOPIC: ATOMIC PROPERTIES OF ELEMENTS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Explain the meaning of periodicity
2. List the atomic properties of elements
3. Explain trends of atomic and ionic sizes in the periodic table.
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; BASIC CHEMISTRY FOR APPLIED SCIENCES by A.S DAN AZUMI.
CONTENT:
Periodicity refers to the reoccurrence of similar properties in a regular pattern in the periodic table.
The early chemists used bulk properties such as density, melting point, molar volumes etc to show periodicity. However, we now know that there is also a periodic variation in the atomic properties of the elements such as the atomic size, ionization energy, electron affinity and electro negativity.
The atomic size of an element may be defined as the distance between the nuclei of two closely approaching atoms of an element. It is determined by the atomic distance of an ion.
EVALUATION:
Define periodicity; what is an atomic size?
ASSIGNMENT:
List the atomic properties of elements as obtained in the periodic table.
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Define ionization energy and electron affinity.
2. Explain the reasons for the trends observed across a period and down a group.
CONTENT:
Ionization energy is the energy required to remove the most loosely bonded electron (valence electron) from an atom in its gaseous form to form a gaseous ion with a positive charge. For elements with more than one electron in their valence shells, then we have 1st, 2nd etc ionization energies.
The ionization energy of an atom increases along a period but decreases down a group. Electron affinity is the energy releases when a gaseous atom gains an electron to form a gaseous negative ion.
Generally, electron affinity increases across a period but decreases down a group in the periodic table.
EVALUATION:
Give two atomic properties that increase along a period in the periodic table.
SUB-TOPIC: ELECTRO-NEGATIVITIES
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Define electro negativity and electro positivity.
2. Show the trend in electro negativity of elements down a period and across a period in the periodic table.
CONTENT:
The electro negativity of an atom is the power of that atom in a molecule to attract electrons.
The electro negativities elements increase across a period but decrease down a group.
The most electro negative elements are the reactive non metals e.g. (fluorine) at the top right corner of the periodic table.
EVALUATION:
Define electro negativity. Which element is most electro negative?
SUB-TOPIC: ATOMIC PROPERTIES OF ELEMENTS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Explain the meaning of periodicity
2. List the atomic properties of elements
3. Explain trends of atomic and ionic sizes in the periodic table.
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; BASIC CHEMISTRY FOR APPLIED SCIENCES by A.S DAN AZUMI.
CONTENT:
Periodicity refers to the reoccurrence of similar properties in a regular pattern in the periodic table.
The early chemists used bulk properties such as density, melting point, molar volumes etc to show periodicity. However, we now know that there is also a periodic variation in the atomic properties of the elements such as the atomic size, ionization energy, electron affinity and electro negativity.
The atomic size of an element may be defined as the distance between the nuclei of two closely approaching atoms of an element. It is determined by the atomic distance of an ion.
EVALUATION:
Define periodicity; what is an atomic size?
ASSIGNMENT:
List the atomic properties of elements as obtained in the periodic table.
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Define ionization energy and electron affinity.
2. Explain the reasons for the trends observed across a period and down a group.
CONTENT:
Ionization energy is the energy required to remove the most loosely bonded electron (valence electron) from an atom in its gaseous form to form a gaseous ion with a positive charge. For elements with more than one electron in their valence shells, then we have 1st, 2nd etc ionization energies.
The ionization energy of an atom increases along a period but decreases down a group. Electron affinity is the energy releases when a gaseous atom gains an electron to form a gaseous negative ion.
Generally, electron affinity increases across a period but decreases down a group in the periodic table.
EVALUATION:
Give two atomic properties that increase along a period in the periodic table.
SUB-TOPIC: ELECTRO-NEGATIVITIES
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Define electro negativity and electro positivity.
2. Show the trend in electro negativity of elements down a period and across a period in the periodic table.
CONTENT:
The electro negativity of an atom is the power of that atom in a molecule to attract electrons.
The electro negativities elements increase across a period but decrease down a group.
The most electro negative elements are the reactive non metals e.g. (fluorine) at the top right corner of the periodic table.
EVALUATION:
Define electro negativity. Which element is most electro negative?
WEEK 3
TOPIC: FAMILIES OF ELEMENTS
SUB-TOPIC: GROUP 1 AND 2 OF THE PERIODIC TABLE
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Identify groups 1 and 2 elements as alkali and alkaline earth metals respectively.
2. Describe the properties of elements in groups 1 and 2.
3. Give the name of the common elements in each group.
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; ESSENTIAL CHEMISTRY FOR SENIOR SCHOOL by O. ODESINA.
CONTENT:
The familiar elements in group 1 are sodium and potassium. They are univalent with one electron only in their valence shells. They are good conductors of electricity. They are electropositive i.e they have a marked tendency to donate electrons.
e.g. Na Na+ + e-
K K+ + e-
They react with cold water vigorously to liberate hydrogen gas and form alkalis; so they are known as alkali metals.
2Na(g) + 2H2O(l) 2Na(aq) + H2(g)
EVALUATION:
What is the family name of group 1 elements?
Why group II elements are called alkaline earth metals?
ASSIGNMENT:
Write briefly, the characteristics of alkali metals.
SUB-TOPIC: GROUPS 3 AND 4 ELEMENTS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Identify elements in groups 3 and 4
2. Give the valencies of these elements
3. Give chemical properties of these elements and some of their compounds.
CONTENT:
The most common element in group 3 is aluminum Ai. It is a trivalent element like other elements in the group. They are electro positive compounds. Aluminum reacts with steam above 6000c to liberate hydrogen. Aluminum oxide and hydroxides are insoluble and amphoteric in nature.
EVALUATION:
What is amphoteric?
Give one example of an amphoteric oxide.
SUB-TOPIC: GROUP 5 AND 6
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Name the elements in groups 5 and 6
2. Give the physical and chemical properties of these elements.
CONTENT:
Nitrogen and phosphorus belong to group 5. They are non metals and show the common valencies of 3 and 5. They are electron acceptors and both form several oxides.
Elements in group 6 include oxygen and sulphur; which are non metals. They are electron acceptors. E.g.
2Mg (s) + O2(g) 2Mg2+ O2-(s)
Oxygen is slightly soluble in water while sulphur is insoluble. Both elements do not attack water in any form. Both combine directly with hydrogen to yield water and hydrogen sulphide respectively.
EVALUATION:
What is the valency of oxygen?
Write the chemical formula of a compound formed between oxygen and sodium.
SUB-TOPIC: GROUP 1 AND 2 OF THE PERIODIC TABLE
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Identify groups 1 and 2 elements as alkali and alkaline earth metals respectively.
2. Describe the properties of elements in groups 1 and 2.
3. Give the name of the common elements in each group.
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; ESSENTIAL CHEMISTRY FOR SENIOR SCHOOL by O. ODESINA.
CONTENT:
The familiar elements in group 1 are sodium and potassium. They are univalent with one electron only in their valence shells. They are good conductors of electricity. They are electropositive i.e they have a marked tendency to donate electrons.
e.g. Na Na+ + e-
K K+ + e-
They react with cold water vigorously to liberate hydrogen gas and form alkalis; so they are known as alkali metals.
2Na(g) + 2H2O(l) 2Na(aq) + H2(g)
EVALUATION:
What is the family name of group 1 elements?
Why group II elements are called alkaline earth metals?
ASSIGNMENT:
Write briefly, the characteristics of alkali metals.
SUB-TOPIC: GROUPS 3 AND 4 ELEMENTS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Identify elements in groups 3 and 4
2. Give the valencies of these elements
3. Give chemical properties of these elements and some of their compounds.
CONTENT:
The most common element in group 3 is aluminum Ai. It is a trivalent element like other elements in the group. They are electro positive compounds. Aluminum reacts with steam above 6000c to liberate hydrogen. Aluminum oxide and hydroxides are insoluble and amphoteric in nature.
EVALUATION:
What is amphoteric?
Give one example of an amphoteric oxide.
SUB-TOPIC: GROUP 5 AND 6
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Name the elements in groups 5 and 6
2. Give the physical and chemical properties of these elements.
CONTENT:
Nitrogen and phosphorus belong to group 5. They are non metals and show the common valencies of 3 and 5. They are electron acceptors and both form several oxides.
Elements in group 6 include oxygen and sulphur; which are non metals. They are electron acceptors. E.g.
2Mg (s) + O2(g) 2Mg2+ O2-(s)
Oxygen is slightly soluble in water while sulphur is insoluble. Both elements do not attack water in any form. Both combine directly with hydrogen to yield water and hydrogen sulphide respectively.
EVALUATION:
What is the valency of oxygen?
Write the chemical formula of a compound formed between oxygen and sodium.
WEEK 4
TOPIC: OXIDATION-REDUCTION REACTIONS
SUB-TOPIC: DEFINITION OF OXIDATION AND REDUCTION
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Give different definitions of oxidation and reduction.
2. Define oxidation in terms of electron transfer and oxidation number.
3. Illustrate these processes with balanced equations.
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO.
CONTENT:
Oxidation-reduction reactions involve two opposing yet complimentary processes. They involve loss and gain of electrons which require the two processes. Every oxidation must be accompanied by a reduction and vice-versa.
Oxidation and reduction passed through several stages of definitions before the present definitions.
Oxidation has been defined as the addition of oxygen and removal of hydrogen while reduction is the opposite.
C(s) + 2ZnO(s) CO2 (g) + 2Zn(s)
EVALUATION:
Give two former definitions of oxidation and reduction.
ASSIGNMENT:
Define oxidation and reduction in terms of oxidation numbers.
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Define oxidation and reduction in terms of oxidation number.
2. List the rules for determining oxidation numbers.
3. Recognize redox reactions.
CONTENT:
Redox reactions can be recognized with the aid of oxidation numbers. Oxidation number of an element in any particular molecule or ion is defined as the electrical charge it appears to have as determined by a set of arbitrary rules.
These rules make it possible to calculate the oxidation numbers for the elements in the reactants and products of a chemical change.
EVALUATION:
Define oxidation and reduction in terms of oxidation number.
SUB-TOPIC: CALCULATION OF OXIDATION NUMBERS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Calculate oxidation numbers of elements in various types of compounds.
2. Determine the oxidation numbers of elements in acidic and basic media.
CONTENT:
During the process of oxidation, a substance loses electron(s) and its oxidation number increases in the positive direction. The reverse is the case for reduction. This point is necessary for consideration when calculating the oxidation numbers. For example, the oxidation number of Cr in K2Cr2O7 is determined as shown below:
2(oxidation no. of K) + 2(oxidation no. of Cr) + 7(oxidation no. of O) = 0.
i.e. 2(+1) + 2(x) + 7 x (-2) = 0
2 + 2x - 14 = 0
2x = 14-2
2x = 12
X =12/2 = + 6
EVALUATION:
Calculate the oxidation numbers of the underlined elements in the following:
(i) SO42-
(ii) HNO3
(iii) PH3
SUB-TOPIC: DEFINITION OF OXIDATION AND REDUCTION
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Give different definitions of oxidation and reduction.
2. Define oxidation in terms of electron transfer and oxidation number.
3. Illustrate these processes with balanced equations.
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO.
CONTENT:
Oxidation-reduction reactions involve two opposing yet complimentary processes. They involve loss and gain of electrons which require the two processes. Every oxidation must be accompanied by a reduction and vice-versa.
Oxidation and reduction passed through several stages of definitions before the present definitions.
Oxidation has been defined as the addition of oxygen and removal of hydrogen while reduction is the opposite.
C(s) + 2ZnO(s) CO2 (g) + 2Zn(s)
EVALUATION:
Give two former definitions of oxidation and reduction.
ASSIGNMENT:
Define oxidation and reduction in terms of oxidation numbers.
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Define oxidation and reduction in terms of oxidation number.
2. List the rules for determining oxidation numbers.
3. Recognize redox reactions.
CONTENT:
Redox reactions can be recognized with the aid of oxidation numbers. Oxidation number of an element in any particular molecule or ion is defined as the electrical charge it appears to have as determined by a set of arbitrary rules.
These rules make it possible to calculate the oxidation numbers for the elements in the reactants and products of a chemical change.
EVALUATION:
Define oxidation and reduction in terms of oxidation number.
SUB-TOPIC: CALCULATION OF OXIDATION NUMBERS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Calculate oxidation numbers of elements in various types of compounds.
2. Determine the oxidation numbers of elements in acidic and basic media.
CONTENT:
During the process of oxidation, a substance loses electron(s) and its oxidation number increases in the positive direction. The reverse is the case for reduction. This point is necessary for consideration when calculating the oxidation numbers. For example, the oxidation number of Cr in K2Cr2O7 is determined as shown below:
2(oxidation no. of K) + 2(oxidation no. of Cr) + 7(oxidation no. of O) = 0.
i.e. 2(+1) + 2(x) + 7 x (-2) = 0
2 + 2x - 14 = 0
2x = 14-2
2x = 12
X =12/2 = + 6
EVALUATION:
Calculate the oxidation numbers of the underlined elements in the following:
(i) SO42-
(ii) HNO3
(iii) PH3
WEEK 5
TOPIC: BALANCING OF REDOX EQUATIONS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. List types of redox reagents.
2. Give examples of redox reagents.
3. List types of redox reactions with chemical equations
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; ESSENTIAL CHEMISTRY by O. ODESINA
CONTENT: TYPES OF REDOX REAGENTS
There are types of redox reagents used in redox reactions; reducing agents and oxidizing agents.
A reducing agent is the substance that loses or donates electrons or gets oxidized or whose oxidation umber increases.
An oxidizing agent is the substance that gains or accepts electrons or gets reduced or whose oxidation number decreases.
All addition and combustion reactions are redox. All displacement reactions are redox. Some decomposition and double decomposition reactions are redox.
EVALUATION: The teacher evaluates the lesson with the following questions:
Teacher asks students to give examples of redox reagents.
ASSIGNMENT:
Give three types of redox reactions with chemical equations.
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Identify reducing agents and give steps for testing for them in the laboratory.
2. Identify oxidizing agents and give the steps for testing them in the laboratory.
CONTENT:
Generally, elements especially metals in groups I, II and III in the periodic table are reducing agents. Other examples are conc. Hcl, aqueous solutions Ki, SnCl2, FeCl2, SO2.
An oxidizing agent is used to test for a reducing agent.
Example:
To the solid substance in a test tube, add a few drops of bench dilute Hcl.
Result:
There is effervescence, the gas given off is colourless, odourless, has no action in most litmus but gives a pop sound with lighted splint.
The gas is hydrogen.
EVALUATION:
Give one test for a solid reducing agent.
ASSIGNMENT:
Name one oxidizing agent and explain how you could test for it in the laboratory.
SUB-TOPIC: BALANCING OF REDOX EQUATIONS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Define and write half equations for any redox equation.
2. Balance half equations in acid and basic media.
3. Write overall redox reactions.
CONTENT:
An equation which represents oxidation or reduction process is called a half equation.
Balancing redox equation involves the following steps:
1. Assign oxidation number to each action of the element in the half equation.
2. Balance the number of atoms on both sides, so as to conform to the law of conservation of mass.
3. Add appropriate number of electrons to accent for the number of electrons lost or gained.
For complex equations, the following steps are added to the above:
4. Add appropriate number of H2O molecules to balance oxygen atoms.
5. Add appropriate number of H+ to balance hydrogen atoms.
6. Check the charge.
EVALUATION:
List the steps involved in balancing of redox equations in acid medium.
ASSIGNMENT:
Balance the following redox equation by ion-electron method
Fe2+ (aq) + Cl2 (g) Fe3+ (aq) + Cl-(aq)
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. List types of redox reagents.
2. Give examples of redox reagents.
3. List types of redox reactions with chemical equations
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; ESSENTIAL CHEMISTRY by O. ODESINA
CONTENT: TYPES OF REDOX REAGENTS
There are types of redox reagents used in redox reactions; reducing agents and oxidizing agents.
A reducing agent is the substance that loses or donates electrons or gets oxidized or whose oxidation umber increases.
An oxidizing agent is the substance that gains or accepts electrons or gets reduced or whose oxidation number decreases.
All addition and combustion reactions are redox. All displacement reactions are redox. Some decomposition and double decomposition reactions are redox.
EVALUATION: The teacher evaluates the lesson with the following questions:
Teacher asks students to give examples of redox reagents.
ASSIGNMENT:
Give three types of redox reactions with chemical equations.
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Identify reducing agents and give steps for testing for them in the laboratory.
2. Identify oxidizing agents and give the steps for testing them in the laboratory.
CONTENT:
Generally, elements especially metals in groups I, II and III in the periodic table are reducing agents. Other examples are conc. Hcl, aqueous solutions Ki, SnCl2, FeCl2, SO2.
An oxidizing agent is used to test for a reducing agent.
Example:
To the solid substance in a test tube, add a few drops of bench dilute Hcl.
Result:
There is effervescence, the gas given off is colourless, odourless, has no action in most litmus but gives a pop sound with lighted splint.
The gas is hydrogen.
EVALUATION:
Give one test for a solid reducing agent.
ASSIGNMENT:
Name one oxidizing agent and explain how you could test for it in the laboratory.
SUB-TOPIC: BALANCING OF REDOX EQUATIONS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Define and write half equations for any redox equation.
2. Balance half equations in acid and basic media.
3. Write overall redox reactions.
CONTENT:
An equation which represents oxidation or reduction process is called a half equation.
Balancing redox equation involves the following steps:
1. Assign oxidation number to each action of the element in the half equation.
2. Balance the number of atoms on both sides, so as to conform to the law of conservation of mass.
3. Add appropriate number of electrons to accent for the number of electrons lost or gained.
For complex equations, the following steps are added to the above:
4. Add appropriate number of H2O molecules to balance oxygen atoms.
5. Add appropriate number of H+ to balance hydrogen atoms.
6. Check the charge.
EVALUATION:
List the steps involved in balancing of redox equations in acid medium.
ASSIGNMENT:
Balance the following redox equation by ion-electron method
Fe2+ (aq) + Cl2 (g) Fe3+ (aq) + Cl-(aq)
WEEK 6
TOPIC: BALANCING COMPLEX HALF EQUATIONS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Break redox equations into half equations.
2. Balance each half equation with respect to atoms.
3. Balance each half equation with respect to charges.
4. Write overall equations eliminating the electrons.
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; ESSENTIAL CHEMISTRY by O. ODESINA
CONTENT:
Complex redox equations are those that involve oxyanims as the oxidizing or reducing agent or both. Such reactions take place in a neutral, an acidic or alkaline medium.
There are steps to follow in order to balance complex half equations. These include:
1. Balance all atoms except those of H and O.
2. Assign oxidation numbers to the atoms that have changed.
3. Add appropriate number of electrons to balance oxygen atoms.
4. Add appropriate number of H2O molecules to balance O atoms.
5. Add appropriate number of H+ to balance hydrogen atoms.
EVALUATION:
Plot the following redox equations into half equations:
MnO4- + H+ Mn2+ + H2O
ASSIGNMENT:
Balance the following half equation in acid medium:
Cr2O72- Cr3+
SUB-TOPIC: BALANCING REDOX EQUATIONS: OXIDATION NUMBER METHOD
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Assign oxidation numbers to atoms in a specie.
2. Equalize charges in oxidation numbers.
CONTENT:
Oxidation umber is used without splitting the redox reaction equation. For example:
Mg + Ag+ Mg2+ + Ag.
The above equation can be balanced as shown below.
1. Assign oxidation number to each atom.
Mg + Ag+ Mg2+ + Ag
O.N O +1 +2 O
Change in O.N of Mg = +2-0=+2 (loss of 2e-)
Change in O.N of Ag= 0 - (+1)= -1; (gain of 1e-)
2. Equalizing charges: for each atom of Mg oxidized Mg+ must be reduced. Hence, multiply Ag by 2:
Mg + 2Ag+ Mg2+ + 2Ag.
EVALUATION:
Balance the following redox equations by the oxidation method.
ASSIGNMENT:
List the steps in using oxidation number method in balancing redox equations.
SUB-TOPIC: SOLVED PROBLEMS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Use electron method to balance redox equations.
2. Use oxidation number method to balance equations.
CONTENT:
In the reaction below:
Zn(s) + Cu2+(aq) Zn2+(aq) + Cu(s)
a. Which metal is reduced and which metal is oxidized?
Solution:
Assign oxidation numbers to the species:
Zn(s) + Cu2+ (aq) Zn2+(aq) + Cu(s)
O.N 0 +2 +2 0
Cu2+ is reduced to Cu, while Zn is oxidized to ZN2+ .
b. Write half equations for the reactions.
Solution:
Oxidation: Zn(s) Zn2+(aq) + 2e-
Reduction: Cu2+(aq) + 2e- Cu(s).
c. State with reason, which is the oxidizing agent and which is the reducing agent.
Solution:
Oxidizing agent: is Cu2+ ; it is reduced
Reducing agent : is Zn; it is oxidized to Zn2+
EVALUATION:
Spilt each of the following equations into two balanced half cell equations.
1. Mg + Fe2+ Mg2+ + Fe
2. Ai + I2 Ai3+ + I-
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Break redox equations into half equations.
2. Balance each half equation with respect to atoms.
3. Balance each half equation with respect to charges.
4. Write overall equations eliminating the electrons.
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; ESSENTIAL CHEMISTRY by O. ODESINA
CONTENT:
Complex redox equations are those that involve oxyanims as the oxidizing or reducing agent or both. Such reactions take place in a neutral, an acidic or alkaline medium.
There are steps to follow in order to balance complex half equations. These include:
1. Balance all atoms except those of H and O.
2. Assign oxidation numbers to the atoms that have changed.
3. Add appropriate number of electrons to balance oxygen atoms.
4. Add appropriate number of H2O molecules to balance O atoms.
5. Add appropriate number of H+ to balance hydrogen atoms.
EVALUATION:
Plot the following redox equations into half equations:
MnO4- + H+ Mn2+ + H2O
ASSIGNMENT:
Balance the following half equation in acid medium:
Cr2O72- Cr3+
SUB-TOPIC: BALANCING REDOX EQUATIONS: OXIDATION NUMBER METHOD
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Assign oxidation numbers to atoms in a specie.
2. Equalize charges in oxidation numbers.
CONTENT:
Oxidation umber is used without splitting the redox reaction equation. For example:
Mg + Ag+ Mg2+ + Ag.
The above equation can be balanced as shown below.
1. Assign oxidation number to each atom.
Mg + Ag+ Mg2+ + Ag
O.N O +1 +2 O
Change in O.N of Mg = +2-0=+2 (loss of 2e-)
Change in O.N of Ag= 0 - (+1)= -1; (gain of 1e-)
2. Equalizing charges: for each atom of Mg oxidized Mg+ must be reduced. Hence, multiply Ag by 2:
Mg + 2Ag+ Mg2+ + 2Ag.
EVALUATION:
Balance the following redox equations by the oxidation method.
ASSIGNMENT:
List the steps in using oxidation number method in balancing redox equations.
SUB-TOPIC: SOLVED PROBLEMS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Use electron method to balance redox equations.
2. Use oxidation number method to balance equations.
CONTENT:
In the reaction below:
Zn(s) + Cu2+(aq) Zn2+(aq) + Cu(s)
a. Which metal is reduced and which metal is oxidized?
Solution:
Assign oxidation numbers to the species:
Zn(s) + Cu2+ (aq) Zn2+(aq) + Cu(s)
O.N 0 +2 +2 0
Cu2+ is reduced to Cu, while Zn is oxidized to ZN2+ .
b. Write half equations for the reactions.
Solution:
Oxidation: Zn(s) Zn2+(aq) + 2e-
Reduction: Cu2+(aq) + 2e- Cu(s).
c. State with reason, which is the oxidizing agent and which is the reducing agent.
Solution:
Oxidizing agent: is Cu2+ ; it is reduced
Reducing agent : is Zn; it is oxidized to Zn2+
EVALUATION:
Spilt each of the following equations into two balanced half cell equations.
1. Mg + Fe2+ Mg2+ + Fe
2. Ai + I2 Ai3+ + I-
WEEK 7
TOPIC: ELECTROLYSES
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. Define common terms used in electrolysis
REFERENCE: ESSENTIAL CHEMISTRY ODESINA, NEW SCHOOL CHEMISTRY, ABABIO
CONTENT: COMMON TERMS USED IN ELECTROLYSIS
i. Electrolysis
ii. Electrolytes and non electrolytes
iii. Metallic conductor
iv. Weak electrolyte
v. Electrodes, cathode and anode
EVALUATION:
What is meant by:
i. Electrolysis
ii. electrolyte
ASSIGNMENT:
Give 3 examples of
i. electrolytic conductor and
ii. weak electrolyte
SUB-TOPIC: SELECTIVE DISCHARGE AND ELECTROLYSIS OF SOME COMPOUNDS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. explain the discharge of ion during electrolysis
ii. explain the electrolysis of H2SO4, NaCl and CUSO4
CONTENT:
The factors affecting the discharge of ions during electrolysis include
1. ionic concentration
2. The nature of the electrode used.
The ion present in the electrolysis of H2SO4 are H+, SO42- and OH-.
H+ is discharged.
The electrolysis of CUSO4, CU is deposited.
EVALUATION:
Give 2 examples of
i. Electrolyte
ii. Weak electrolyte
ASSIGNMENT:
State and explain 3 factors affecting the discharge of ion during electrolysis
SUB-TOPIC: ELECTROLYSIS OF CUSO4
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. Explain the electrolysis of CUSO4
CONTENT:
The anode dissolves and deposit at the cathode. The blue colour remains unchanged in the electrolysis of CUSO4 using copper electrodes.
EVALUATION:
Name the ions present in the electrolysis of CUSO4
ASSIGNMENT:
Explain the following:
i. Electrolysis of CUSO4 using cu-cu electrode
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. Define common terms used in electrolysis
REFERENCE: ESSENTIAL CHEMISTRY ODESINA, NEW SCHOOL CHEMISTRY, ABABIO
CONTENT: COMMON TERMS USED IN ELECTROLYSIS
i. Electrolysis
ii. Electrolytes and non electrolytes
iii. Metallic conductor
iv. Weak electrolyte
v. Electrodes, cathode and anode
EVALUATION:
What is meant by:
i. Electrolysis
ii. electrolyte
ASSIGNMENT:
Give 3 examples of
i. electrolytic conductor and
ii. weak electrolyte
SUB-TOPIC: SELECTIVE DISCHARGE AND ELECTROLYSIS OF SOME COMPOUNDS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. explain the discharge of ion during electrolysis
ii. explain the electrolysis of H2SO4, NaCl and CUSO4
CONTENT:
The factors affecting the discharge of ions during electrolysis include
1. ionic concentration
2. The nature of the electrode used.
The ion present in the electrolysis of H2SO4 are H+, SO42- and OH-.
H+ is discharged.
The electrolysis of CUSO4, CU is deposited.
EVALUATION:
Give 2 examples of
i. Electrolyte
ii. Weak electrolyte
ASSIGNMENT:
State and explain 3 factors affecting the discharge of ion during electrolysis
SUB-TOPIC: ELECTROLYSIS OF CUSO4
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. Explain the electrolysis of CUSO4
CONTENT:
The anode dissolves and deposit at the cathode. The blue colour remains unchanged in the electrolysis of CUSO4 using copper electrodes.
EVALUATION:
Name the ions present in the electrolysis of CUSO4
ASSIGNMENT:
Explain the following:
i. Electrolysis of CUSO4 using cu-cu electrode
WEEK 8
TOPIC: ELECTROLYSES
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. State and explain Faraday's first law of electrolysis
REFERENCE: ESSENTIAL CHEMISTRY ODESINA, NEW SCHOOL CHEMISTRY, ABABIO
CONTENT:
Faraday's first law of electrolysis states that the mass (m) of a substance liberated at the electrode is directly proportional to the quantity of electricity (Q) passing through the electrolyte
M α Q , Q = It
M = EIt
EVALUATION:
State Faraday's first law of electrolysis
ASSIGNMENT:
Draw the diagram for the electrolytic extraction of copper
SUB-TOPIC: CALCULATION USING FARADAY'S FIRST LAW OF ELECTROLYSIS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. Carry out simple calculations based on Faraday's first law of electrolysis
CONTENT:
Calculate the current that must be passed into a solution of aluminum salt for 1hr.30 minutes in order to deposit 1.5g of Aluminum. (AL = 27)
Solution:
Mass of AL deposited = 1.5g
Current in amperes =?
Time = 90 x 60s
Q = It
= 1 x 90 x 60
=5400I
Al3+ + 3e- AL
Therefore:
1.5g of AL will be deposited by
3 x 96500 x 1.5
27
= 16083.3 Ci
Thus 5400I = 16083.3
I = 16083.3 = 2.93A
5400
EVALUATION:
State Faraday's first law of electrolysis
ASSIGNMENT:
In the electrolysis of a solution of CUSO4 using CU electrodes, these results were obtained:
Mass of CU anode before expt = 13.00g
Mass of CU anode after expt = 7.00g
Mass of CU cathode before expt = 10.0g
1. What was the mass of the cathode after the expt?
2. Explain what happened to the concentration of the solution during the electrolysis
SUB-TOPIC: FARADAY'S SECOND LAW AND USES OF ELECTROLYSIS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. State and explain Faraday's 2nd law and the state the uses of electrolysis
CONTENT:
Faraday's 2nd law states that when the same quantity of electricity is passed through different electrolytes, the relative number of moles of the elements deposited are inversely proportional to the charge on the ions of the elements.
Uses of electrolysis include
M -EIT
EVALUATION:
State Faraday's 1st law of electrolysis
ASSIGNMENT:
Draw the diagram for the electrolytic extraction of copper.
SUB-TOPIC: CALCULATION USING FARADAY'S 1ST LAW OF ELECTRLYSIS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. Carry out simple calculations based on Faraday's 1st law of electrolysis
REFERENCE: ESSENTIAL CHEMISTRY ODESINA, NEW SCHOOL CHEMISTRY, ABABIO
CONTENT:
Calculate the current that must be passed into solution of Aluminum salt for 1hr.30mins in order to deposit 1.5g of Al. (Al=27)
Solution:
Mass of Al deposited = 1.5g
Current in amperes?
Time = 90 x 60
Q= It
= I x 90 x 60 = 5400I
Al3+ + 3e- Al
Therefore:
1.5 of Al will be deposited by
3 x 96500 x 15
27
= 16083.3C
I= 16083.3 = 2.93A
EVALUATION:
State Faraday's 1st law of electrolysis.
ASSIGNMENT:
Explain the following terms:
a. Electrolyte
b. Ionic theory
c. State Faraday's first law of electrolysis
SUB-TOPIC: FARADAY'S 2ND LAW OF ELECTROLYSIS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
Explain Faraday's 2nd law of electrolysis
REFERENCE: ESSENTIAL CHEMISTRY ODESINA, NEW SCHOOL CHEMISTRY, ABABIO
CONTENT:
Faraday's 2nd law states that when the same quantity of electrolysis is passed through different electrolytes. The relative number of moles of element deposited are inversely proportional to the ion.
It is used for extraction.
EVALUATION:
State Faraday's 2nd law of electrolysis
ASSIGNMENT:
Read and draw the diagram for the verification of Faraday's 2nd law
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. State and explain Faraday's first law of electrolysis
REFERENCE: ESSENTIAL CHEMISTRY ODESINA, NEW SCHOOL CHEMISTRY, ABABIO
CONTENT:
Faraday's first law of electrolysis states that the mass (m) of a substance liberated at the electrode is directly proportional to the quantity of electricity (Q) passing through the electrolyte
M α Q , Q = It
M = EIt
EVALUATION:
State Faraday's first law of electrolysis
ASSIGNMENT:
Draw the diagram for the electrolytic extraction of copper
SUB-TOPIC: CALCULATION USING FARADAY'S FIRST LAW OF ELECTROLYSIS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. Carry out simple calculations based on Faraday's first law of electrolysis
CONTENT:
Calculate the current that must be passed into a solution of aluminum salt for 1hr.30 minutes in order to deposit 1.5g of Aluminum. (AL = 27)
Solution:
Mass of AL deposited = 1.5g
Current in amperes =?
Time = 90 x 60s
Q = It
= 1 x 90 x 60
=5400I
Al3+ + 3e- AL
Therefore:
1.5g of AL will be deposited by
3 x 96500 x 1.5
27
= 16083.3 Ci
Thus 5400I = 16083.3
I = 16083.3 = 2.93A
5400
EVALUATION:
State Faraday's first law of electrolysis
ASSIGNMENT:
In the electrolysis of a solution of CUSO4 using CU electrodes, these results were obtained:
Mass of CU anode before expt = 13.00g
Mass of CU anode after expt = 7.00g
Mass of CU cathode before expt = 10.0g
1. What was the mass of the cathode after the expt?
2. Explain what happened to the concentration of the solution during the electrolysis
SUB-TOPIC: FARADAY'S SECOND LAW AND USES OF ELECTROLYSIS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. State and explain Faraday's 2nd law and the state the uses of electrolysis
CONTENT:
Faraday's 2nd law states that when the same quantity of electricity is passed through different electrolytes, the relative number of moles of the elements deposited are inversely proportional to the charge on the ions of the elements.
Uses of electrolysis include
M -EIT
EVALUATION:
State Faraday's 1st law of electrolysis
ASSIGNMENT:
Draw the diagram for the electrolytic extraction of copper.
SUB-TOPIC: CALCULATION USING FARADAY'S 1ST LAW OF ELECTRLYSIS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
i. Carry out simple calculations based on Faraday's 1st law of electrolysis
REFERENCE: ESSENTIAL CHEMISTRY ODESINA, NEW SCHOOL CHEMISTRY, ABABIO
CONTENT:
Calculate the current that must be passed into solution of Aluminum salt for 1hr.30mins in order to deposit 1.5g of Al. (Al=27)
Solution:
Mass of Al deposited = 1.5g
Current in amperes?
Time = 90 x 60
Q= It
= I x 90 x 60 = 5400I
Al3+ + 3e- Al
Therefore:
1.5 of Al will be deposited by
3 x 96500 x 15
27
= 16083.3C
I= 16083.3 = 2.93A
EVALUATION:
State Faraday's 1st law of electrolysis.
ASSIGNMENT:
Explain the following terms:
a. Electrolyte
b. Ionic theory
c. State Faraday's first law of electrolysis
SUB-TOPIC: FARADAY'S 2ND LAW OF ELECTROLYSIS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
Explain Faraday's 2nd law of electrolysis
REFERENCE: ESSENTIAL CHEMISTRY ODESINA, NEW SCHOOL CHEMISTRY, ABABIO
CONTENT:
Faraday's 2nd law states that when the same quantity of electrolysis is passed through different electrolytes. The relative number of moles of element deposited are inversely proportional to the ion.
It is used for extraction.
EVALUATION:
State Faraday's 2nd law of electrolysis
ASSIGNMENT:
Read and draw the diagram for the verification of Faraday's 2nd law
WEEK 9
TOPIC: ELECTRO CHEMISTRY
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Define electrode potential.
2. Describe standard electrode and electrode potential.
3. Measure electrode potential
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; ESSENTIAL CHEMISTRY by O. ODESINA
CONTENT:
When a metal pole is placed in a solution containing its ions, a potential difference develops between the metal and the solution of its ions which is known as electrode potential of the metal ions/metal system.
The standard set up between the metal and one molar solution of its ions at 250c (arbitrarily taking that of hydrogen ions/hydrogen gas system as zero.
To measure the standard elective potential of a metal ions/metal system, the half cell is connected to that of a hydrogen half cell by a self bridge , the voltmeter indicates the potential difference.
EVALUATION:
Define standard electrode potential of a metal.
ASSIGNMENT: Explain briefly how standard electrode potential of a metal ion/metal system is measured.
SUB-TOPIC: ELECTRO CHEMICAL CELLS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Tell what electro chemical cell is.
2. Construct and label Daniel cell.
3. Differentiate between a primary cell and a secondary cell.
CONTENT:
Redox reaction can be used to produce electrical current in a device called electro chemical cell. An electro chemical cell is therefore a device which converts chemical reactions into an electrical current.
The main requirement in constructing this cell is that the oxidizing and reducing agents are separated from each other so that electron transfer could occur through the electrodes to the separate reaction.
Zn(s) + CuSo4(aq) Cu(s) + ZnSo4(aq)
This reaction can be separated into half equations:
Zn(s) Zn2+ (aq) + 2e- (oxidation)
Cu2+ (aq) + 2e- Cu(s) (reduction)
EVALUATION:
Define an electro chemical cell.
ASSIGNMENT:
Give two differences between primary cell and secondary cells.
TOPIC: ELECTROCHEMISTRY
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
REFERENCE: ESSENTIAL CHEMISTRY ODESINA, NEW SCHOOL CHEMISTRY, ABABIO
CONTENT:
The device in which chemical energy is converted to electrical energy is called an electrochemical cell, voltaic cell or galvanic cell. It consists of oxidation half reaction and reduction half reaction.
EVALUATION:
What is electrochemical cell?
ASSIGNMENT:
Read the differences between electrolytic cell and electro chemical cell.
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Define electrode potential.
2. Describe standard electrode and electrode potential.
3. Measure electrode potential
REFERENCE: NEW SCHOOL CHEMISTRY by ABABIO; ESSENTIAL CHEMISTRY by O. ODESINA
CONTENT:
When a metal pole is placed in a solution containing its ions, a potential difference develops between the metal and the solution of its ions which is known as electrode potential of the metal ions/metal system.
The standard set up between the metal and one molar solution of its ions at 250c (arbitrarily taking that of hydrogen ions/hydrogen gas system as zero.
To measure the standard elective potential of a metal ions/metal system, the half cell is connected to that of a hydrogen half cell by a self bridge , the voltmeter indicates the potential difference.
EVALUATION:
Define standard electrode potential of a metal.
ASSIGNMENT: Explain briefly how standard electrode potential of a metal ion/metal system is measured.
SUB-TOPIC: ELECTRO CHEMICAL CELLS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Tell what electro chemical cell is.
2. Construct and label Daniel cell.
3. Differentiate between a primary cell and a secondary cell.
CONTENT:
Redox reaction can be used to produce electrical current in a device called electro chemical cell. An electro chemical cell is therefore a device which converts chemical reactions into an electrical current.
The main requirement in constructing this cell is that the oxidizing and reducing agents are separated from each other so that electron transfer could occur through the electrodes to the separate reaction.
Zn(s) + CuSo4(aq) Cu(s) + ZnSo4(aq)
This reaction can be separated into half equations:
Zn(s) Zn2+ (aq) + 2e- (oxidation)
Cu2+ (aq) + 2e- Cu(s) (reduction)
EVALUATION:
Define an electro chemical cell.
ASSIGNMENT:
Give two differences between primary cell and secondary cells.
TOPIC: ELECTROCHEMISTRY
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
REFERENCE: ESSENTIAL CHEMISTRY ODESINA, NEW SCHOOL CHEMISTRY, ABABIO
CONTENT:
The device in which chemical energy is converted to electrical energy is called an electrochemical cell, voltaic cell or galvanic cell. It consists of oxidation half reaction and reduction half reaction.
EVALUATION:
What is electrochemical cell?
ASSIGNMENT:
Read the differences between electrolytic cell and electro chemical cell.