BIOLOGY LESSON NOTE ON HUMAN KIDNEY

Image
Lesson Note on the Human Kidney Topic: The Human Kidney Duration: 40 minutes Specific Objectives: By the end of the lesson, students should be able to: Define the kidney and state its location in the human body. Identify and describe the structure and functions of the kidney. Explain the processes involved in urine formation (filtration, reabsorption, and secretion). Describe how the kidney contributes to homeostasis. Identify common kidney-related diseases and how to prevent them. Evaluate the importance of maintaining kidney health. Lesson Content: 1. Introduction to the Human Kidney The kidneys are vital organs in the human body responsible for filtering waste from the blood and regulating water and electrolyte balance. They are part of the excretory system and play a crucial role in homeostasis. Location: The kidneys are located in the abdominal cavity, on either side of the spine, just below the rib cage. Each kidney is bean-shaped and about the size of a fi...

Chemistry Lesson Note On Electrolysis – Electrolytes, Electrodes, Faraday’s Laws


Topic: Electrolysis – Electrolytes, Electrodes, Faraday’s Laws

Class: SS1


Specific Objectives:

By the end of the lesson, students should be able to:

  1. Define electrolysis and related terms like electrolyte and electrodes.
  2. Identify different types of electrolytes and electrodes.
  3. Explain the principles of electrolysis.
  4. State and apply Faraday’s First and Second Laws of Electrolysis.
  5. Solve basic calculations using Faraday’s laws.

Instructional Materials:

  • Electrolysis setup (e.g., electrolytic cell with battery, wires, electrodes)
  • Beaker with dilute acid (HCl or H₂SO₄), sodium chloride solution, or copper(II) sulfate
  • Diagrams of electrolysis setup
  • Chart showing Faraday’s laws
  • Voltmeter, ammeter, stopwatch

Lesson Content:

Step 1: Meaning of Electrolysis

Electrolysis is the chemical decomposition of a compound (electrolyte) in molten or aqueous solution by the passage of electric current.

  • It involves breaking chemical bonds using electricity.

Step 2: Important Terms

  1. Electrolyte: A substance that conducts electricity and undergoes chemical changes during electrolysis (e.g., NaCl solution, CuSO₄ solution).
  2. Electrodes: Conductors through which electric current enters or leaves the electrolyte.
    • Anode: Positive electrode
    • Cathode: Negative electrode
  3. Ions: Charged particles that move towards electrodes (Cations to cathode, Anions to anode).
  4. Electrolytic Cell: Apparatus used to carry out electrolysis.

Step 3: Electrolysis Process (Example: Electrolysis of Copper(II) Sulfate Solution)

Setup:

  • Electrolyte: Copper(II) sulfate (CuSO₄) solution
  • Electrodes: Copper electrodes
  • When current passes:
    • Cu²⁺ ions migrate to the cathode and gain electrons → deposited as Cu metal
    • SO₄²⁻ or OH⁻ ions migrate to the anode and lose electrons → form oxygen gas

Half-equations:

  • At cathode: Cu²⁺ + 2e⁻ → Cu(s)
  • At anode: 2H₂O → O₂(g) + 4H⁺ + 4e⁻

Step 4: Faraday’s Laws of Electrolysis

First Law:
The mass of a substance deposited or liberated at an electrode is directly proportional to the quantity of electricity passed.

Mathematical expression:

Where:

  • m = mass deposited (g)
  • E = equivalent weight
  • I = current (A)
  • t = time (s)
  • F = Faraday's constant (96500 C/mol)

Second Law:
When the same quantity of electricity is passed through different electrolytes, the mass of substances liberated is proportional to their chemical equivalent weights.


Step 5: Application of Faraday’s Laws (Sample Calculation)

Example:
Calculate the mass of copper deposited when a current of 2A is passed through copper(II) sulfate solution for 30 minutes.
Atomic mass of Cu = 63.5; n = 2

Solution:


So, 1.18 g of copper is deposited.


Evaluation:

  1. Define electrolysis.
  2. Differentiate between anode and cathode.
  3. State Faraday’s First Law of Electrolysis.
  4. What is the mass of silver deposited when 9650 C of electricity is passed through silver nitrate solution? (Ag = 108; n = 1)
  5. Write the electrode reactions for electrolysis of NaCl solution.

Homework:

  1. Draw and label the electrolysis setup for copper(II) sulfate using graphite electrodes.
  2. Explain what happens at each electrode.
  3. A current of 3 A is passed for 20 minutes through a solution of silver nitrate. Calculate the mass of silver deposited.

Conclusion:

Electrolysis is a vital chemical process used in industries like electroplating, metal extraction, and purification. Understanding the basic principles and calculations is essential for mastering electrochemistry.

Comments

Popular posts from this blog

CHEMISTRY LESSON NOTE FOR SS1, SS2 AND SS3 pdf

PHYSICS LESSON NOTE FOR SS1 SS2 AND SS3

WEEK 2: PEST AND DISEASES OF CROPS