This checkpoint tests Block A: chemical vs physical changes, signs of reactions, acids and bases, the pH scale, indicators, neutralisation, and environmental applications.
This checkpoint assesses your understanding of the fundamentals of chemical reactions and acids and bases.
Chemical vs physical changes, signs of reactions, conservation of mass.
Acids and bases, pH scale, common examples, properties.
Indicators, testing pH, natural vs synthetic indicators.
Neutralisation: acid + base -> salt + water, everyday examples.
Acid rain, ocean acidification, Indigenous knowledge of soil chemistry.
1. Which of the following is a sign that a chemical reaction has occurred?
2. What does the law of conservation of mass state?
3. Which pH value indicates a neutral substance?
4. What colour does universal indicator turn in a strong acid?
5. In a neutralisation reaction, what are the products?
6. A farmer adds lime (calcium hydroxide) to acidic soil. What type of reaction is this?
7. Which of the following is a natural pH indicator?
8. A student burns 4 g of magnesium in a sealed container. The final mass is 6.6 g. What mass of oxygen reacted?
9. What is the main cause of ocean acidification?
10. A white powder is tested with universal indicator and turns red. When baking soda is added, the solution turns green and bubbles form. Which conclusion is best supported?
11. Describe the pH scale and explain what pH values indicate acidic, neutral and alkaline substances. Include two examples of each. 4 MARKS
12. Explain how an antacid tablet works to relieve heartburn. Use the terms acid, base and neutralisation in your answer. 4 MARKS
13. A student claims that "boiling water is a chemical reaction because bubbles form." Explain why this claim is incorrect, and describe what would be better evidence of a chemical reaction. 4 MARKS
Tick when you have finished all questions and reviewed your answers.