COAS Chemistry2 Teacher ResourcesOriginal material © Cambridge University Press 2005, 2007, 2009 1
14 Worksheet 1
Chemical properties of transition elements
1Aqueous sodium hydroxide was added separately to three different coloured solutions:
•solution A gave a dark green precipitate
•solution B gave a blue precipitate
•solution C gave a rusty brown precipitate.
aWhich of the three solutions being tested might have been aqueous iron(III) sulfate?[1]
bWrite a balanced chemical equation for the reaction between aqueous sodium
hydroxide and aqueous iron(III) sulfate. Include state symbols.[2]
cWhich of the three solutions being tested might have been aqueous copper(II) sulfate?[1]
dWrite balanced symbol and ionic equations for the reaction between aqueous sodium hydroxide and aqueous copper(II) sulfate. Include state symbols. [4]
eWhich of the three solutions being tested might have been aqueous iron(II) chloride?[1]
fWrite a balanced symbol and ionic equations for the reaction between aqueous sodium hydroxide and aqueous iron(II) chloride. Include state symbols. [4]
gThese reactions involve precipitation. Could they also be termed redox reactions?
Explain your answer.[2]
2Iron(II) chloride solution reacts with chlorine in aqueous solution to give a solution
of iron(III) chloride.
aWrite a balanced chemical equation for this reaction.[1]
bWrite an ionic equation for this reaction.[1]
cIdentify the substance oxidised and the substance reduced in this reaction.[2]
3Potassium manganate(VII) solution reacts with a solution of iron(II) sulfate in the
presence of sulfuric acid. The products of this reaction are iron(III) sulfate solution,
manganese(II) sulfate solution, potassium sulfate solution and water. Each potassium manganate(VII) formula unit reacts with five iron(II) sulfate formula units.
aWrite a balanced chemical equation for this reaction.[1]
bWrite an ionic equation for this reaction.[1]
cIdentify the substance oxidised and the substance reduced in this reaction.[2]
4The reaction in question 3 can be used to find the concentration of an iron(II) sulfate solution
by titration. For example, 25.0 cm3 of iron(II) sulfate solution of unknown concentration
reacted with exactly 16.3 cm3 of 0.0200 mol dm–3 potassium manganate(VII) solutionin a
titration of this type.
Assume the iron(II) sulfate used to make up the solution was anhydrous.
(Mr values: Fe = 55.8, S = 32.1, O = 16.0)
aHow many moles of potassium manganate(VII) are contained in 16.3 cm3 of
0.0200 mol dm–3 solution?[1]
bHow many moles of iron(II) sulfate were present in the 25.0 cm3 of
iron(II) sulfate solution?[1]
cCalculate the concentration of the iron(II) sulfate solution, in mol dm–3.[1]
dCalculate the concentration of the iron(II) sulfate solution, in g dm–3.[2]
Total: Score: %
COAS Chemistry2 Teacher ResourcesOriginal material © Cambridge University Press 2005, 2007, 2009 1