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3.1 Introducing chemical reactions

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Question 30

Excess magnesium is added to hydrochloric acid. The equation for the reaction is:

Mg+2HCl→MgCl2+H2 \mathrm{Mg + 2HCl \rightarrow MgCl_{2} + H_{2}} Mg+2HCl→MgCl2​+H2​

When the reaction stops, 19.06 g of magnesium chloride has been made.

Relative atomic mass (ArA_rAr​): H = 1.0 Mg = 24.3 Cl = 35.5

Calculate the mass of hydrogen chloride, HCl\mathrm{HCl}HCl, that reacted.

[3]
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3.1 Introducing chemical reactions Questions

  1. GCSE
  2. /Chemistry
  3. /3.1 Introducing chemical reactions

134 exam-style questions on OCR GCSE Chemistry 3.1 Introducing chemical reactions, covering 3.1.1 Writing formulae and balanced chemical equations, 3.1.2 Formulae of compounds from ions, and state symbols, 3.1.3 Conservation of mass and observed changes in mass, 3.1.4 Half equations and balanced ionic equations, 3.1.5 The mole and the Avogadro constant, and 3.1.6 Stoichiometry, limiting reactants and reacting masses. Each one has a worked solution and a mark scheme showing where the marks go.

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