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Year 10 Science — Acidic, basic and neutral substances

Sort everyday substances as acidic, basic or neutral, read what each natural indicator is telling you, and use neutralisation to explain an ant bite and a sour field.

Name: ________________________

  1. 1.Which of these did the litmus tests find to be basic?

    • a) Baking soda solution
    • b) Amla juice
    • c) Sugar solution
    • d) Vinegar

  2. 2.Red rose extract has been added to each of these three test tubes. Tap the tube holding a basic solution.

    Write the number of the part.

    123

  3. 3.Each of these was tested with blue and red litmus paper. Sort them by the nature the papers reported.

    Groups: Acidic · Basic · Neutral

    • Vinegar
    • Tamarind water
    • Soap solution
    • Lemon juice
    • Lime water
    • Sugar solution
    • Washing powder solution
    • Salt solution

  4. 4.A substance that shows one colour in an acid and a different colour in a base has a two-word name in this chapter. What is it?

  5. 5.An acid solution and a base solution are mixed in the right amounts and the result is neither acidic nor basic. What is this reaction called?

  6. 6.A red ant bites, and moist baking soda rubbed on the spot relieves the stinging. Why does that work?

    • a) Baking soda is an acid and washes the sting away
    • b) Baking soda is a base and neutralises the acid the ant injected
    • c) Baking soda turns the acid into a stronger acid that numbs the skin
    • d) Baking soda dries the skin so the sting cannot spread

  7. 7.Put the steps of making a red rose indicator back into the order the chapter gives them.

    • Crush the petals with a mortar and pestle
    • Filter off the coloured liquid and keep it as the extract
    • Pour hot water over the crushed petals and cover the tumbler
    • Wash the fallen rose petals in water

  8. 8.Match each problem to the treatment the chapter gives for it.

    • Soil that is too acidic
    • Soil that is basic
    • Acidic factory waste
    • treated with a basic substance before release
    • treated with lime
    • treated with manure and composted leaves

Answer key — Year 10 Science — Acidic, basic and neutral substances

  1. 1. a) Baking soda solution
  2. 2. 2 — Basic
  3. 3. Lemon juice → Acidic; Tamarind water → Acidic; Vinegar → Acidic; Soap solution → Basic; Lime water → Basic; Washing powder solution → Basic; Sugar solution → Neutral; Salt solution → Neutral
  4. 4.
    • acid-base indicator
    • acid base indicator
    • indicator
  5. 5.
    • neutralisation
    • neutralization
    • a neutralisation reaction
    • neutralisation reaction
  6. 6. b) Baking soda is a base and neutralises the acid the ant injected
  7. 7. 1. Wash the fallen rose petals in water 2. Crush the petals with a mortar and pestle 3. Pour hot water over the crushed petals and cover the tumbler 4. Filter off the coloured liquid and keep it as the extract
  8. 8. Soil that is too acidic → treated with lime; Soil that is basic → treated with manure and composted leaves; Acidic factory waste → treated with a basic substance before release