Using the Earth's resources and obtaining potable water

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Question 6
Medium

This question is about treating and testing water.

A water treatment facility is testing a local water supply after an accidental leakage of iron(III) chloride (FeCl3\text{FeCl}_3FeCl3​) into a holding reservoir.

a.

Draw one line from each treatment step to the main reason for that step.

  • Step:

    • Coagulation
    • Sterilisation

  • Reason for step:

    • Kill harmful microbes
    • Remove large floating debris
    • Cause small suspended particles to clump together
    • Neutralise acidic compounds
[2]
b.

Which two of the following substances are commonly used to sterilise fresh drinking water? Choose two options.

  • Chlorine
  • Nitrogen
  • Ozone
  • Carbon dioxide
  • Helium
[2]
c.

Which two methods can demonstrate the presence of dissolved solids in a sample of water?

  • Test the sample's boiling point.
  • Check if the liquid turns blue cobalt chloride paper pink.
  • Evaporate all the liquid to see if a solid residue remains.
  • Add universal indicator solution to the sample.
[2]
d.

Separate samples are tested to identify the ions present in the iron(III) chloride contaminant. Draw one line from each ion to the correct chemical reagent needed to identify it.

  • Ion:

    • Iron(III) ion (Fe3+\text{Fe}^{3+}Fe3+)
    • Chloride ion (Cl−\text{Cl}^-Cl−)

  • Reagent:

    • Barium chloride solution
    • Silver nitrate solution
    • Sodium hydroxide solution
    • Dilute hydrochloric acid
[2]
e.

How can pure water be produced from a sample of water containing dissolved solids?

  • Chromatography
  • Decanting
  • Distillation
  • Filtration
[1]

Using the Earth's resources and obtaining potable water Questions

  1. GCSE
  2. /Chemistry
  3. /Using the Earth's resources and obtaining potable water