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3.1 Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations

3.1 Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations

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Question 17

An analytical chemist is investigating the composition of potassium dichromate (K2Cr2O7\text{K}_2\text{Cr}_2\text{O}_7K2​Cr2​O7​), a strong oxidizing agent historically used in laboratory titrations and safety breathalyzers.

Calculate the percentage (%) by mass of chromium in potassium dichromate. Give your answer to 3 significant figures.

Relative atomic mass (ArA_rAr​): Cr=52.0\text{Cr} = 52.0Cr=52.0.

Relative formula mass (MrM_rMr​): K2Cr2O7=294.2\text{K}_2\text{Cr}_2\text{O}_7 = 294.2K2​Cr2​O7​=294.2.

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3.1 Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations Questions

  1. GCSE
  2. /Chemistry
  3. /3.1 Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations

53 exam-style questions on AQA GCSE Chemistry 3.1 Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations, covering 3.1.1 Conservation of mass and balanced chemical equations, 3.1.2 Relative formula mass, 3.1.3 Mass changes when a reactant or product is a gas, and 3.1.4 Chemical measurements. Each one has a worked solution and a mark scheme showing where the marks go.

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