A student puts a piece of copper wire into colourless silver nitrate solution.
After a few hours, silver crystals have formed on the wire and the solution has turned blue.
The equation for the reaction is:
Cu+2AgNO3→Cu(NO3)2+2Ag \mathrm{Cu + 2AgNO_{3} \rightarrow Cu(NO_{3})_{2} + 2Ag} Cu+2AgNO3→Cu(NO3)2+2AgWrite the balanced ionic equation for this reaction. Include state symbols.
In the reaction, copper atoms lose electrons and silver ions gain electrons.
Write the half equation for each change.
Copper: ......
Silver: ......
Explain, using your half equations, why two silver ions react with each copper atom.
The copper wire loses 0.635 g of copper during the reaction.
Relative atomic mass (Ar): Ag = 107.9, Cu = 63.5
Calculate the mass of silver that forms.
Give your answer to 3 significant figures.
Mass of silver = ...... g
In a different experiment, the student mixes lead(II) nitrate solution with potassium iodide solution.
A yellow precipitate of lead(II) iodide forms. Lead(II) ions are Pb²⁺.
Write the balanced ionic equation for this reaction. Include state symbols.
55 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.