Multiple Choice Questions (MCQ) topic quiz
Developing metals
Instructions and answers for teachers
These instructions cover the student activity section which can be found on page 9. This
Lesson Element supports OCR A Level Chemistry B (Salters).
When distributing the activity section to the students either as a printed copy or as a
Word file you will need to remove the teacher instructions section.
The Activity
This Lesson Element is a teaching and learning resource containing 10 multiple choice
questions (MCQs) on the theme of developing metals. Some questions might require
synoptic thinking, using knowledge and ideas from various topics across the full A Level
content.
This resource can be used to test and consolidate understanding at the end of a topic or to
revisit and refresh knowledge at a later point in the course.
Learning Outcomes
This Lesson Element relates to the specification learning outcomes DM(b), DM(c), DM(d),
DM(e), DM(f), DM(g), DM(h), DM(j), DM(k), DM(m), DM(n).
Introduction
Multiple choice questions allow rapid coverage of a wide range of sub-topics.
Contrary to a widespread belief among students, multiple choice questions are not
necessarily easy – they can be easy, moderate or difficult.
The questions are written so that the incorrect answers are plausible distractors based on
common errors or misconceptions.
The questions in this quiz cover topics mainly from specification sections:
Developing metals.
Version 1
1
© OCR 2016
Multiple Choice Questions (MCQ) topic quiz - answers
1.
Atoms of which transition element have only 1 electron in the 4s subshell?
A
cobalt
Both of the metals that have one electron in
the 4s subshell begin with C (copper and
chromium) and so the learner may have tried
to rote learn rather than work out the metals.
B
chromium
Correct answer: Chromium’s outer electron
configuration is 4s13d5.
C
scandium
Scandium has one electron in its 3d subshell,
not the 4s.
D
zinc
The learner may be thinking of zinc as being
an ‘exception’ to the usual rules (it is not a
transition metal) but is confused about the
reason why.
Your answer
2.
Which of these electron configurations correctly represents a transition metal ion?
A
[Ar]4s23d8
This electron configuration is not possible in a
transition metal ion as electrons are always
removed from the 4s subshell first.
B
[Ar]4s13d9
This is an unstable electron configuration
which would never occur. Ten outer electrons
could either represent a nickel atom (4s23d8)
or a Cu+/Zn2+ ion (4s03d10).
C
[Ar]4s03d9
Correct answer: This represents a Cu2+ ion.
D
[Ar]4s04d8
This electron configuration is not possible as
it combines 4s and 4d subshells.
Your answer
Version 1
B
2
C
© OCR 2016
3.
A pale green solution produces a dark green precipitate when aqueous sodium
hydroxide is added.
What is the likely formula of the complex ion present in the original solution?
A
[CuCl4]2–
While this complex of copper could produce a
slightly green colour (closer to yellow), it
would not produce a dark green precipitate
on addition of hydroxide ions.
B
[Fe(H2O)4(OH)2]
This is the formula of the precipitate formed,
not the final solution.
C
[Fe(H2O)6]2+
Correct answer: The solution contains the
hexaaqua iron(II) complex which is
deprotonated on addition of hydroxide to form
the precipitate in answer B.
D
[Fe(H2O)6]3+
This is the iron(III) complex which would
produce a red-brown precipitate.
Your answer
Version 1
3
C
© OCR 2016
4.
Dichromate(VI) ions can be reduced by zinc powder in acidic solution:
wCr2O72–(aq) + 14H+(aq) + xZn(s)  yCr3+(aq) + 7H2O(l) + zZn2+(aq)
What are the correct values of w, x, y and z in order to balance the equation?
A
1, 1, 2, 3
This reaction is balanced in terms of the
charges but not in terms of the oxidation
states or numbers of zinc atoms.
B
2, 3, 2, 3
The learner has correctly balanced most of
the equation but accidentally doubled the
moles of dichromate ions, perhaps missing
the fact that there are two chromium atoms in
the formula.
C
1, 3, 2, 3
Correct answer: Two dichromate(VI) ions
are reduced to two Cr3+ ions, meaning six
electrons are gained. Each zinc atom loses
two electrons so three zinc atoms and ions
are required.
D
3, 3, 2, 3
The learner is confused about the best way to
balance the reaction and is either guessing or
confusing the charge on ions with the number
of particles.
Your answer
5.
Which equation represents a redox reaction?
A
Fe(OH)2(s)  FeO(s) + H2O(l)
This is a dehydration reaction as the iron(II)
hydroxide loses a water molecule.
B
2Fe(OH)2(s) + ½O2(g) + H2O(l)
 2Fe(OH)3(s)
Correct answer: Oxygen is reduced when it
reacts with water to form hydroxide and
iron(II) is oxidised to iron(III).
C
[Fe(H2O)6]3+(aq) + 3OH–(aq) 
[Fe(H2O)3(OH)3](s) + 3H2O(l)
This is a deprotonation reaction to form a
precipitate.
D
[Fe(H2O)6]2+(aq) + 2OH–(aq) 
[Fe(H2O)4(OH)2](s) + 2H2O(l)
As above, this is a deprotonation reaction
only.
Your answer
Version 1
C
4
B
© OCR 2016
6.
The ethanedioate ion, C2O42–, forms an octahedral complex with Fe3+ ions in solution.
Which option gives the correct information for this complex?
A
B
C
D
Co-ordination number
Number of ligands
3
6
6
8
6
3
6
4
Overall charge of
complex ion
–3
–3
–9
–5
A
The learner has mixed up co-ordination number with number of ligands.
B
Correct answer: The ethanedioate ion forms six dative bonds from three
ligands as it is bidentate; the overall charge is –3 as the three
ethanedioate ions have a cumulative charge of –6 and the iron has a
charge of +3.
C
The learner has neglected to realise that the ethanedioate ion is
bidentate and so has assumed six ligands for an octahedral complex.
D
The learner has identified that the ligand is bidentate but has been
confused by the term ‘octahedral’ and has assumed this means eight
dative bonds.
Your answer
Version 1
5
B
© OCR 2016
7.
An electrochemical cell can be formed by connecting half-cells for the following
reactions:
Cu2+(aq) + 2e–
Fe3+(aq) + e–
Cu(s)
Fe2+(aq)
Eo = +0.34 V
Eo = +0.77 V
Which statement about this cell is true?
A
Copper atoms are oxidised.
Correct answer: The copper half-cell has a
less positive electrode potential so the copper
atoms will lose electrons to form copper(II)
ions.
B
Ecell = +1.11 V
Both electrode potentials are positive so the
Ecell cannot be calculated by adding them
together.
C
Electrons flow from the iron halfcell to the copper half-cell.
The copper half-cell loses electrons (see A)
so they will flow from the copper half-cell to
the iron half-cell.
D
Fe2+ ions are acting as oxidising
agents.
The Fe3+ ions are the ones accepting
electrons and so they are oxidising agents –
Fe2+ ions are produced in the reaction.
Your answer
8.
Which statement is correct for the use of a colorimeter to determine the concentration
of a solution of manganate(VII) ions?
A
The absorbance of several
different solutions of a known
concentration should be
determined.
Correct answer: A calibration curve would
be required – a series of dilutions of a known
concentration of solution can be used to
create this.
B
The colorimeter gives a direct
reading of concentration.
The colorimeter can only read relative units of
absorbance – the calibration curve is required
to convert absorbance to concentration.
C
The filter should be similar colour
to the solution.
The filter should be a complementary colour
to the solution so that maximum absorbance
is achieved.
D
The reference should be a
1 mol dm–3 sample of the solution.
The reference should be a sample of water
only.
Your answer
Version 1
A
6
A
© OCR 2016
9.
Which statement is true for a solution of copper(II) sulfate?
A
Blue light is absorbed and
complementary colours are
transmitted.
Blue light is transmitted and complementary
colours (red and green) are absorbed.
B
Excited electrons emit blue light
as they fall back down to their
original energy level.
Electrons absorb visible light when they are
excited but do not re-emit this energy as light.
C
The d-orbitals are split by the
presence of the sulfate ions.
The d-orbitals are split by the water ligands,
hence anhydrous copper(II) sulfate being
white.
D
The frequency of absorbed light is
directly proportional to the energy
difference between d-orbitals.
Correct answer: E = h. The frequency is
related to the energy difference by Planck’s
constant, h.
Your answer
10.
D
Which statement(s) is/are true for all transition metal elements?
Statement 1: Their ions can form complexes with ligands.
Statement 2: They can form compounds in which the metal has a positive or
negative oxidation state.
Statement 3: They form ions with a partially filled 3d sub-shell.
A
1, 2 and 3
Statement 1 is true. Statement 2 is untrue –
the learner is thinking perhaps about the
ability to form positive or negative ions (e.g.
Mn2+, MnO7–) but the oxidation state of the
transition metal is always positive. Statement
3 is also untrue – the learner is forgetting that
the d-block contains more than one period!
B
only 1 and 2
See above for why statements 2 and 3 are
untrue.
C
only 2 and 3
See above for why statements 2 and 3 are
untrue.
D
only 1
Correct answer: True – all transition metal
ions can form complexes.
Your answer
Version 1
7
D
© OCR 2016
This resource has been produced as part of our free Chemistry teaching and learning support package. All the Chemistry teaching and
learning resources, including delivery guides, topic exploration packs, lesson elements and more are available on the qualification
webpages.
If you are looking for examination practice materials, you can find Sample Assessment Materials (SAMs) and a link to the Practice
Papers on the qualification webpages: Chemistry A, Chemistry B.
We’d like to know your view on the resources we produce. By clicking on ‘Like’ or ‘Dislike’ you can help us to ensure that our resources
work for you. When the email template pops up please add additional comments if you wish and then just click ‘Send’. Thank you.
If you do not currently offer this OCR qualification but would like to do so, please complete the Expression of Interest Form which can
be found here: www.ocr.org.uk/expression-of-interest
OCR Resources: the small print
OCR’s resources are provided to support the teaching of OCR specifications, but in no way constitute an endorsed teaching method that is required by the Board, and the decision to
use them lies with the individual teacher. Whilst every effort is made to ensure the accuracy of the content, OCR cannot be held responsible for any errors or omissions within these
resources.
© OCR 2016 - This resource may be freely copied and distributed, as long as the OCR logo and this message remain intact and OCR is acknowledged as the originator of this work.
OCR acknowledges the use of the following content: n/a
Please get in touch if you want to discuss the accessibility of resources we offer to support delivery of our qualifications: resources.feedback@ocr.org.uk
Version 1
8
© OCR 2016
Multiple Choice Questions (MCQ) topic quiz
Developing metals
Learner Activity
1.
Atoms of which transition element have only 1 electron in the 4s subshell?
A
cobalt
B
chromium
C
scandium
D
zinc
Your answer
2.
Which of these electron configurations correctly represents a transition metal ion?
A
[Ar]4s23d8
B
[Ar]4s13d9
C
[Ar]4s03d9
D
[Ar]4s04d8
Your answer
Version 1
9
© OCR 2016
3.
A pale green solution produces a dark green precipitate when aqueous sodium
hydroxide is added.
What is the likely formula of the complex ion present in the original solution?
A
[CuCl4]2–
B
[Fe(H2O)4(OH)2]
C
[Fe(H2O)6]2+
D
[Fe(H2O)6]3+
Your answer
4.
Dichromate(VI) ions can be reduced by zinc powder in acidic solution:
wCr2O72–(aq) + 14H+(aq) + xZn(s)  yCr3+(aq) + 7H2O(l) + zZn2+(aq)
What are the correct values of w, x, y and z in order to balance the equation?
A
1, 1, 2, 3
B
2, 3, 2, 3
C
1, 3, 2, 3
D
3, 3, 2, 3
Your answer
5.
Which equation represents a redox reaction?
A
Fe(OH)2(s)  FeO(s) + H2O(l)
B
2Fe(OH)2(s) + ½O2(g) + H2O(l)  2Fe(OH)3(s)
C
[Fe(H2O)6]3+(aq) + 3OH–(aq)  [Fe(H2O)3(OH)3](s) + 3H2O(l)
D
[Fe(H2O)6]2+(aq) + 2OH–(aq)  [Fe(H2O)4(OH)2](s) + 2H2O(l)
Your answer
Version 1
10
© OCR 2016
6.
The ethanedioate ion, C2O42–, forms an octahedral complex with Fe3+ ions in solution.
Which option gives the correct information for this complex?
A
B
C
D
Co-ordination number
Number of ligands
3
6
6
8
6
3
6
4
Overall charge of
complex ion
–3
–3
–9
–5
Your answer
7.
An electrochemical cell can be formed by connecting half-cells for the following
reactions:
Cu2+(aq) + 2e–
Fe3+(aq) + e–
Cu(s)
Fe2+(aq)
Eo = +0.34 V
Eo = +0.77 V
Which statement about this cell is true?
A
Copper atoms are oxidised.
B
Ecell = +1.11 V
C
Electrons flow from the iron half-cell to the copper half-cell.
D
Fe2+ ions are acting as oxidising agents.
Your answer
8.
Which statement is correct for the use of a colorimeter to determine the concentration
of a solution of manganate(VII) ions?
A
The absorbance of several different solutions of a known concentration
should be determined.
B
The colorimeter gives a direct reading of concentration.
C
The filter should be similar colour to the solution.
D
The reference should be a 1 mol dm–3 sample of the solution.
Your answer
Version 1
11
© OCR 2016
9.
Which statement is true for a solution of copper(II) sulfate?
A
Blue light is absorbed and complementary colours are transmitted.
B
Excited electrons emit blue light as they fall back down to their original energy
level.
C
The d-orbitals are split by the presence of the sulfate ions.
D
The frequency of absorbed light is directly proportional to the energy difference
between d-orbitals.
Your answer
10.
Which statement(s) is/are true for all transition metal elements?
Statement 1: Their ions can form complexes with ligands.
Statement 2: They can form compounds in which the metal has a positive or
negative oxidation state.
Statement 3: They form ions with a partially filled 3d sub-shell.
A
1, 2 and 3
B
only 1 and 2
C
only 2 and 3
D
only 1
Your answer
Version 1
12
© OCR 2016