This question is about ionic compounds.
(a) Draw dot-and-cross diagrams of the ions in magnesium hydroxide, showing the
outer shell electrons only.
Use × for magnesium electrons, ● for oxygen electrons and for each
hydrogen electron.
(2)
(b) Which definition correctly describes the enthalpy change of solution, Δ H ?
sol
(1)
Enthalpy change of solution, Δ H
sol
The enthalpy change when 1 mol of gaseous ions dissolves in
A
sufficient water to give an infinitely dilute solution.
The enthalpy change when 1 mol of an ionic substance dissolves in
B
water to give an infinitely dilute solution.
The enthalpy change when 1 mol of gaseous ions dissolves in
C
sufficient water to give a solution of concentration 1 mol dm−3 .
The enthalpy change when 1 mol of an ionic substance dissolves in
D
water to give a solution of concentration 1 mol dm−3 .
*P76895A02028*
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(c) The table shows the information needed to calculate the
standard enthalpy change of formation of magnesium fluoride.
Label Description Value / kJ mol−1
A enthalpy change of formation of magnesium fluoride
B lattice energy of magnesium fluoride −2957
C enthalpy change of atomisation of magnesium +148
D 1st ionisation energy of magnesium +738
E 2nd ionisation energy of magnesium +1451
F enthalpy change of atomisation of fluorine +79
G 1st electron affinity of fluorine −328
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
This question is about energy changes involved in the formation of ionic compounds.
(a) What is the order of increasing first ionisation energy for the elements beryllium,
helium and lithium?
(1)
A lithium < helium < beryllium
B beryllium < lithium < helium
C helium < beryllium < lithium
D lithium < beryllium < helium
(b) The second ionisation energy of calcium has a magnitude of 1150 kJ mol–1.
Which of the following represents the second ionisation energy of calcium?
(1)
A Ca(g) → Ca2+(g) + 2e– ΔHd = +1150 kJ mol–1
B Ca+(g) → Ca2+(g) + e– ΔHd = +1150 kJ mol–1
C Ca(g) → Ca2+(g) + 2e– ΔHd = –1150 kJ mol–1
D Ca+(g) → Ca2+(g) + e– ΔHd = –1150 kJ mol–1
(c) The formation of potassium ions can be represented by the equation
K(s) → K+(g) + e–
Which statement corresponds to the energy change for this process?
(1)
A the first electron affinity of potassium
B the first ionisation energy of potassium
C the sum of the enthalpy change of atomisation of potassium and the first
electron affinity of potassium
D the sum of the enthalpy change of atomisation of potassium and the first
ionisation energy of potassium
Question
Mathematics
Edexcel2023
First ionisation energy of Ca(g) 590
Electron affinity of Cl(g) –349
Calculate the second ionisation energy of calcium, in kJ mol–1.
(2)
(Total for Question 2 = 8 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
Chemistry
CAIE2022
The table shows the first ionisation energies of elements in Period 3.
Element: Na Mg Al Si P S Cl Ar
IE₁ /kJ/mol: 496 738 577 786 1012 1000 1251 1521
(a) Define the term first ionisation energy.
(b) Explain the general increasing trend in first ionisation energies across Period 3.
(c) Explain why the first ionisation energy of Al is lower than that of Mg.
(d) Explain why the first ionisation energy of S is lower than that of P.
[8 marks]
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
C 4OH – (aq) → 2H (g) + 2O (g) + 4e–
Question
Mathematics
Edexcel2022
2
D 2H O(l) → 4H + (aq) + O (g) + 4e–
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
*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
Mathematics
Edexcel2021
*P65463A0728*
Turn over
PPMMTT
(c) A sodium atom has 11 protons whereas a potassium atom has 19 protons.
Explain why the first ionisation energy of sodium is greater than that of potassium.
(3)
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Question
Mathematics
Edexcel2021
*P65463A0828*
PPMMTT
(d) The successive ionisation energies for magnesium are given in the table.
Electron
number 1 2 3 4 5 6 7 8 9 10 11 12
removed
Ionisation
energy 738 1451 7733 10 541 13 629 17 995 21 704 25 657 31 644 35 463 169 996 189 371
/ kJ mol–1
Log
(ionisation 2.87 3.16 3.89 4.02 4.13 4.34 4.41 4.50 4.55 5.23
energy)
(i) Complete the table.
(1)
(ii) Give a reason why the logarithm of the ionisation energy, rather than just the
ionisation energy, is used to plot a graph.
(1)
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(iii) Give a reason why the successive ionisation energies increase.
(1)
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Question
Mathematics
Edexcel2021
*P65463A0928*
Turn over
PPMMTT
(iv) Plot the graph of log(ionisation energy) against electron number removed.
Join the individual points using straight lines.
(3)
(v) Identify on the graph, using a circle, the points that represent the removal of
the electrons in the outermost energy level of magnesium.
(1)
Question
Mathematics
Edexcel2021
*P65463A01028*
PPMMTT
(e) Estimate a value for the first ionisation energy of oxygen given the data in the table.
(1)
Element First ionisation energy / kJ mol–1
carbon 1086
nitrogen 1402
oxygen
................
(Total for Question 4 = 15 marks)
Question
Mathematics
Edexcel2021
Ionisation energies provide information about the number of electrons and the
arrangement of the electrons in an atom of an element.
(a) A student’s definition of first ionisation energy is shown.
First ionisation energy is the energy released when one mole of gaseous atoms
loses one mole of electrons to form one mole of gaseous 1+ ions.
There is one incorrect word in the student’s definition.
Identify the word, giving the reason why this word is incorrect.
(2)
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(b) Write an equation for the second ionisation energy of oxygen.
Include state symbols.
(2)
Question
Mathematics
Edexcel2020
*P62668A0324*
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(c) The graph shows the first ionisation energies (IE) of eight successive elements
from the first 20 elements in the Periodic Table.
Which letter represents the first ionisation energy of oxygen?
(e)
(b) (d)
(a)
(c)
1st IE / kJ mol−1
(g)
(f) (h)
Atomic number
(1)
A (a)
B (b)
C (c)
D (h)
(d) Give the formula of a stable ion that is isoelectronic with the
magnesium ion, Mg2+.
(1)
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Question
Mathematics
Edexcel2020
(a) Which equation shows the third ionisation energy of aluminium?
(1)
A Al(g) → Al3+(g) + 3e−
B Al2+(g) → Al3+(g) + e−
C Al3+(g) + 3e− → Al(g)
D Al3+(g) + e− → Al2+(g)
(b) Which element in this table is in Group 2?
Ionisation energy / kJ mol−1
Element First Second Third Fourth
W 1086 2353 4621 6223
X 653 1592 2987 4740
Y 590 1145 4912 6474
Z 496 4563 6913 9544
(1)
A W
B X
C Y
D Z
Question
Mathematics
Edexcel2019
First ionisation energy of sodium
+496 kJ mol–1
Na(g) + ½H (g)
Question
Mathematics
Edexcel2018
This question is about ions and ionic compounds.
(a) The first three ionisation energies of calcium are shown in the table.
First ionisation Second ionisation Third ionisation
Ionisation energy
590 1145 4912
/ kJ mol−1
Orbital
(i) Complete the table by identifying the specific orbital from which each
electron is removed.
(2)
(ii) Write the equation for the third ionisation energy of calcium.
Include state symbols.
(1)
(iii) Explain why the difference between the second and third ionisation energies
of calcium is much larger than the difference between the first and second
ionisation energies.
(2)
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Question
Mathematics
Edexcel2017
*P48058A01428*
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(b) The table shows the enthalpy changes needed to calculate the first electron affinity
of bromine.
Value
Enthalpy change
/ kJ mol–1
enthalpy change of atomisation of magnesium, (cid:168) H [Mg(s)] +148
at
1st ionisation energy of magnesium, 1st IE[Mg(g)] +738
2nd ionisation energy of magnesium, 2nd IE[Mg+(g)] +1 451
enthalpy change of atomisation of bromine, (cid:168) H [½Br (l)] +112 at 2
lattice energy of magnesium bromide, LE[MgBr (s)] –2 440
Question
Mathematics
Edexcel2017
*P48058A01528*
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(ii) Calculate the first electron affinity of bromine, in kJ mol–1.
(2)
(c) (i) The first ionisation energy of sodium is 496 kJ mol–1.
Explain why the first ionisation energy of magnesium is higher than that of sodium.
(3)
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(ii) Write the equation, including state symbols, to show the
third ionisation energy of magnesium.
(1)
(Total for Question 6 = 11 marks)