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3.2 Methods of separating and purifying substances

3.2 Methods of separating and purifying substances

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Question 57

Table 1 shows the results of an analytical assay on a sample of high-pressure boiler feed-water collected at a power generation facility.

Table 1: Concentration of trace impurities in the boiler feed-water sample

Dissolved speciesConcentration in mg dm−3\text{mg dm}^{-3}mg dm−3
Magnesium (Mg2+{\text{Mg}}^{2+}Mg2+)0.45
Silica (SiO2{\text{SiO}}_2SiO2​)0.12
Sodium (Na+{\text{Na}}^+Na+)0.08
Chloride (Cl−{\text{Cl}}^-Cl−)0.15
Sulfate (SO42−{{\text{SO}}_4}^{2-}SO4​2−)0.05

Using the data provided in Table 1, explain why this boiler feed-water sample cannot be classified as chemically pure water.

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3.2 Methods of separating and purifying substances Questions

  1. GCSE
  2. /Chemistry
  3. /3.2 Methods of separating and purifying substances

107 exam-style questions on Edexcel GCSE Chemistry 3.2 Methods of separating and purifying substances, covering 3.2.1 Pure substances and mixtures, 3.2.2 Techniques for separating mixtures, 3.2.3 Paper chromatography and Rf values, and 3.2.4 Making water potable. Each one has a worked solution and a mark scheme showing where the marks go.

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