*P76895A01328*
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PMT
(c) Give two reasons for the difference between your calculated values in (a) and (b).
(2)
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(d) In the Direct Ethanol Fuel Cell under acidic conditions, at one electrode the
ethanol is oxidised in the presence of water to produce carbon dioxide, hydrogen
ions and electrons.
At the other electrode, the hydrogen ions and electrons combine with oxygen to
form water.
Write the two ionic half-equations for this process.
State symbols are not required.
(2)
Oxidation half-equation
Reduction half-equation
(Total for Question 5 = 10 marks)
*P76895A01428*
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PMT
*6 Explain why aqueous solutions of Cu2+ ions and Fe2+ ions are coloured but have
different colours, whereas aqueous solutions of Zn2+ ions are colourless.
Include any relevant electronic configurations.
(6)
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Question
Mathematics
Edexcel2023
This question is about chromium and chromium compounds.
(a) Naturally occurring chromium has four isotopes, 50Cr, 52Cr, 53Cr and 54Cr.
State what is meant by the term isotopes.
(2)
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(b) Both chromium and calcium can form ions with a +2 charge.
(i) Complete the electronic configuration of a Cr2+ ion.
(1)
1s2
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(ii) Explain which of chromium or calcium most easily forms a +2 ion using all of
the data in the table.
Atomic 1st ionisation energy 2nd ionisation energy Metallic radius
Element
number / kJ mol–1 / kJ mol–1 / nm
Chromium 24 653 1592 0.129
Calcium 20 590 1145 0.197
(3)
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Question
Mathematics
Edexcel2023
(a) Complete the electronic configuration for the vanadium atom and the V3+ ion.
(2)
V 1s2 2s2 2p6 3s2
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V3+ 1s2 2s2 2p6 3s2
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Question
Mathematics
Edexcel2023
Chemists often use the term ‘orbital’ when considering atomic structure.
(a) State what is meant by the term orbital.
(2)
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(b) Draw diagrams to show the shape of an s and a p orbital.
(2)
s orbital p orbital
(c) What is the electronic configuration of a copper atom?
(1)
A [Ar]4s13d10
B [Ar]4s23d9
C [Ar]4s24p13d8
D [Ar]4s24p23d7
(Total for Question 2 = 5 marks)
Question
Mathematics
Edexcel2022
2
Calculate the molar volume of hydrogen from the results of this experiment.
Include units in your answer.
(2)
(Total for Question 2 = 9 marks)
Question
Mathematics
Edexcel2022
2
B Br (aq) + 2NaF(aq) → 2NaBr(aq) + F (aq)
Question
Mathematics
Edexcel2022
2
C Cl (aq) + 2NaBr(aq) → 2NaCl(aq) + Br (aq)
Question
Mathematics
Edexcel2022
2
D Cl (aq) + 2NaF(aq) → 2NaCl(aq) + F (aq)
Question
Mathematics
Edexcel2022
2
(c) The halogens can form halide ions during reactions.
Complete the electronic configuration of the chloride ion.
(1)
1s2
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Question
Mathematics
Edexcel2022
2HOBr(aq) + 2H+(aq) + 2e– Br (aq) + 2H O(l) Ed = +1.57 V
Question
Mathematics
Edexcel2022
2
(i) Explain why the disproportionation of bromine in water is not
thermodynamically feasible under standard conditions.
Include the overall equation for the disproportionation and its Ed value.
cell
(3)
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(ii) Bromine disproportionates in water to a small extent at 298 K.
Give a possible reason why this reaction occurs.
(1)
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Question
Mathematics
Edexcel2022
though it has fewer electrons in its molecules
• the density of ice at 0 °C is less than that of water at 0 °C.
Explain these properties.
You should include a labelled diagram to show the intermolecular forces between
two molecules of water.
(6)
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2
(c) Lead-acid batteries are used as storage cells in some cars.
The electrolyte is sulfuric acid, one electrode is lead and the other is
lead(IV) oxide, PbO .
Question
Mathematics
Edexcel2022
As the cell discharges, the lead and the lead(IV) oxide are both converted to
solid lead(II) sulfate, PbSO , and the concentration of the sulfuric acid decreases.
Question
Mathematics
Edexcel2022
7 2
(i) Write the overall equation for the reduction of dichromate(VI) ions to
chromium(III) ions by zinc in acid conditions.
State symbols are not required.
(2)
(ii) Calculate Ed for the reaction in (c)(i).
cell
(1)
(iii) Predict whether or not a further reduction of chromium(III) ions to
chromium(II) ions will occur. Justify your answer.
(1)
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Question
Mathematics
Edexcel2022
7 2
Determine, using the experimental data, the brand of nail that was analysed.
(5)
Question
Mathematics
Edexcel2022
2
B 2H (g) + 2O (g) + 4e– → 4OH – (aq)
Question
Mathematics
Edexcel2022
2
D 2H O(l) → 4H + (aq) + O (g) + 4e–
Question
Mathematics
Edexcel2022
2
C 4OH – (aq) → 2H (g) + 2O (g) + 4e–
Question
Mathematics
Edexcel2022
*P67093RA0232*
PMT
Answer ALL questions.
Some questions must be answered with a cross in a box .
If you change your mind about an answer, put a line through the box
and then mark your new answer with a cross .
Question
Mathematics
Edexcel2022
This question is about the elements in Group 2 of the Periodic Table.
(a) Magnesium powder is added to a beaker of water containing a few drops of
Universal Indicator.
The apparatus is set up as shown and allowed to stand for a few days.
test tube filled with water
water and Universal Indicator
filter funnel
magnesium powder
State two changes that will be seen after a few days.
(2)
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(b) Explain how the trend in the reactivity of the Group 2 elements is determined by
their electronic configurations.
(3)
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Question
Mathematics
Edexcel2022
2
Explain, in terms of electrons, why this is a redox reaction.
(2)
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(d) An experiment was carried out to determine the molar volume of hydrogen at
room temperature.
Question
Chemistry
CAIE2021
Copper is a transition metal.
(a) State two general properties of transition metals that are not shown by the s-block metals in Period 4.
(b) Write the electronic configuration of Cu²⁺.
(c) Explain why transition metal compounds are often coloured.
[7 marks]
Mathematics
Edexcel2020
*P62668A0424*
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PMT
(e) A student stated that ‘the elements scandium and zinc are d-block elements but
are not transition metals’.
Discuss this statement, using appropriate electronic configurations to support
your answer.
(4)
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(Total for Question 1 = 8 marks)
Question
Mathematics
Edexcel2018
This question is about transition metals.
(a) Which of these ions has the electronic configuration [Ar]3d5?
(1)
A Cr3+
B Fe2+
C Mn2+
D Mn3+
(b) In which of these complex ions does the transition metal have the
oxidation number +3?
(1)
A [Ag(CN) ]−
Question
Mathematics
Edexcel2017
Iron and zinc are in the d-block of the Periodic Table.
(a) Which of these is the electronic configuration of an iron(II) ion, Fe2+?
(1)
3d 4s
A [Ar] (cid:110)(cid:112) (cid:110)(cid:112) (cid:110)(cid:112)
B [Ar] (cid:110)(cid:112) (cid:110) (cid:110) (cid:110) (cid:110)
C [Ar] (cid:110)(cid:112) (cid:110)(cid:112) (cid:110)(cid:112)
D [Ar] (cid:110) (cid:110) (cid:110) (cid:110) (cid:110)(cid:112)
(b) Iron(II) ions, [Fe(H O) ]2+, form a pale green solution but zinc ions, [Zn(H O) ]2+,