Lesson Notes By Weeks and Term - Senior Secondary 2

TERM׃ 3^RD TERM

WEEK FIVE

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 5 periods each

Date:

Subject: Chemistry

Topic:- Ionic theory

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Define ionic bonding
2. Define covalent bonding.
3. Differentiate between electrolytes and non electrolytes.
4. Identify strong and weak Electrolytes
5. Define electrochemical series and identify factors that affect the preferential discharge of ions

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers,

demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

NOTE

IONIC THEORY

Electrovalent compounds, also known as ionic compounds, are formed through the transfer of electrons from one atom to another. This transfer results in the formation of positive and negative ions, which are held together by electrostatic forces.

  - Bonding: Involves the transfer of electrons.

  - Nature of Bond: Ionic bond.

- Examples:(NaCl), (CaO).

Covalent compounds, on the other hand, are formed by the sharing of electrons between atoms. In these compounds, electrons are shared in pairs, creating molecular structures. Examples include water (H₂O), where oxygen and hydrogen share electrons, and methane (CH₄), where carbon and hydrogen share electrons.

  - Bonding: Involves the sharing of electrons.

  - Nature of Bond: Covalent bond.

  - Examples: (H₂O), (CH₄).

Electrolytes and Non-electrolytes

Electrolytes and non-electrolytes are substances based on their ability to conduct electricity.

1. Electrolytes are substances that, when dissolved in water or melted, produce ions and can conduct electricity.

   - Types:

     - Strong Electrolytes: Dissociate completely into ions. Examples include strong acids (HCl) and ionic salts (NaCl).

     - Weak Electrolytes: Partially dissociate into ions. Examples include weak acids (acetic acid, CH₃COOH.

2. Non-electrolytes: are substances that do not produce ions in solution and do not conduct electricity.

   - Examples: Molecular compounds with covalent bonds, such as sugar C₁₂H₂₂O₁₁, or non-ionic gases like N₂ and O₂

Electrochemical Series

The electrochemical series, also known as the electromotive force (EMF) series or the standard electrode potential series, is a list of metals and hydrogen arranged in order of their standard electrode potentials. This series helps predict the direction of spontaneous redox reactions and provides insights into the relative strengths of oxidizing and reducing agents.

1. Higher on the Series

   - More Reactive as a Reducing Agent: Metals or species higher on the series are more likely to be oxidized (act as reducing agents) in a redox reaction.                                

For example, in the series, metals like lithium and sodium are more reactive (stronger reducing agents), while metals like gold and platinum are less reactive (weaker reducing agents). The electrochemical series is a useful tool in understanding and predicting the behavior of elements in electrochemical cells and redox reactions.

Factors affecting the preferential discharge of ions

The preferential discharge of ions during electrolysis is influenced by several factors:

1. Standard Electrode Potentials
2. Concentration of Ions
3. Temperature
4. Nature of Electrodes

EVALUATION:   1. Define Ionic bond

2. Differentiate between electrolytes and non electrolytes
3. What is electrochemical series?
4. Identify 4 factors affecting the preferential discharge of ions.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively