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Chemical formulae, equations and calculations

Chemical formulae, equations and calculations

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Question 15

Some older fire extinguishers and dry-cleaning solvents contained chlorinated organic compounds that have since been phased out due to environmental concerns. One such compound has the following composition by mass:

  • Carbon: 24.2%
  • Hydrogen: 4.0%
  • Chlorine: 71.8%
a.

Calculate the empirical formula of this compound. [Relative atomic masses: C=12\text{C} = 12C=12, H=1\text{H} = 1H=1, Cl=35.5\text{Cl} = 35.5Cl=35.5]

[3]
b.

The relative formula mass (MrM_rMr​) of this compound is 99. State its molecular formula.

[2]
Markscheme

Chemical formulae, equations and calculations Questions

  1. IGCSE
  2. /Chemistry
  3. /Chemical formulae, equations and calculations

80 exam-style questions on Edexcel IGCSE Chemistry Chemical formulae, equations and calculations. Each one has a worked solution and a mark scheme showing where the marks go.

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