ChalkHour

Year 7 Science: Acids and alkalis lesson pack

A complete, ready-to-teach KS3 lesson on acids and alkalis. Below is a real sample of what ChalkHour makes: the full pack adds three levels of worksheet, model answers, a teaching explainer and print-ready PDF and Word files.

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Real sample

Acids, Alkalis and the pH Scale

This lesson introduces Year 7 students to the chemical properties of acids and alkalis. It covers the pH scale (0-14), the use of indicators to identify substances, and the concept of neutralisation. Students will learn to distinguish between concentrated/dilute and strong/weak substances while maintaining safety in the lab.

Learning objectives

  • Identify common household acids and alkalis and their position on the pH scale.
  • Describe the use of indicators, specifically Universal Indicator and litmus paper, to measure pH.
  • Explain the process of neutralisation and identify the products formed.
  • Compare the properties of strong and weak acids/alkalis using the pH scale.

Lesson plan (60 minutes)

  1. Introduction · 5 min

    Do Now: Students sort a list of substances (lemon juice, soap, vinegar, bleach) into 'acidic' or 'alkaline' based on prior knowledge.

  2. Direct Instruction · 10 min

    Teacher Explainer: Walkthrough of the pH scale, indicators, and safety symbols. Demonstration of Universal Indicator in HCl and NaOH.

  3. Guided Practice · 5 min

    Vocabulary Match-up: Students define key terms using the teaching notes.

  4. Independent Practice · 25 min

    Main Activity: Differentiated worksheets. Students work through Support, Core, or Stretch tasks based on teacher assessment.

  5. Assessment · 10 min

    8-Question Multiple Choice Quiz to check for understanding.

  6. Review · 5 min

    Plenary: Reviewing the 'Misconception of the Day' - are all acids dangerous? Discussion on stomach acid and fruit.

Key vocabulary

Acid
A substance with a pH less than 7. Turns Universal Indicator red, orange, or yellow.
Alkali
A soluble base with a pH greater than 7. Turns Universal Indicator blue or purple.
pH Scale
A scale from 0-14 used to measure how acidic or alkaline a solution is.
Indicator
A substance that changes colour to show the pH of a solution.
Neutral
A substance with a pH of 7, such as pure water.

Core worksheet (first questions)

  1. 1. Define the term 'indicator'.
  2. 2. What are the colours of Universal Indicator for a strong acid, a neutral solution, and a strong alkali?
  3. 3. Classify these two household items: Lemon Juice and Oven Cleaner.
  4. 4. Why is Universal Indicator more useful than Litmus paper?

Quiz (sample)

  1. 1. What is the pH range for an acidic solution?

    • A. pH 0-6
    • B. pH 7
    • C. pH 8-14
    • D. pH 1-14

  2. 2. What colour does Universal Indicator turn in a neutral solution?

    • A. Red
    • B. Blue
    • C. Green
    • D. Purple

  3. 3. Which of these is a strong acid?

    • A. Lemon juice
    • B. Baking soda
    • C. Hydrochloric acid
    • D. Distilled water

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Support and Stretch worksheets, every answer and model answer, the teaching explainer and common misconceptions, editable and ready to print as PDF or Word.

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