4
solution of concentration 0.0450 mol dm−3?
The molar mass of K SO is 174.3 g mol−1.
Question
Mathematics
Edexcel2024
4
(1)
A 1.96 g
B 7.84 g
C 19.6 g
D 31.4 g
(Total for Question 3 = 10 marks)
Question
Mathematics
Edexcel2024
2
Question
Mathematics
Edexcel2024
2
Question
Mathematics
Edexcel2024
4
propanoic acid CH CH COOH 2.94
Question
Mathematics
Edexcel2024
3 3
(i) Write the expression for the acid dissociation constant, K , for carbonic acid.
a
State symbols are not required.
(1)
(ii) A blood sample taken from an individual was analysed.
Calculate the pH of the blood sample.
Use your expression for K and the values shown.
a
K for carbonic acid = 4.50 × 10−7 mol dm−3
a
[HCO–] = 0.0240 mol dm−3 [H CO ] = 0.00200 mol dm−3
Question
Mathematics
Edexcel2024
2 2 3
Equilibrium 2 H CO (aq) H+(aq) + HCO−(aq)
Question
Mathematics
Edexcel2024
3 3
(i) When a person exercises vigorously the concentration of carbon dioxide (aq)
in the blood increases.
Explain how this increase in the concentration of carbon dioxide affects the
pH of the blood.
Refer to the equilibria in your answer. No calculation is required.
(2)
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
(ii) Explain how the carbonic acid–hydrogencarbonate buffer system in
Equilibrium 2 acts to restore the pH of the blood after a person has exercised.
(2)
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
(Total for Question 4 = 14 marks)
Question
Mathematics
Edexcel2024
5 2 2 2
(a) Calculate the enthalpy change for the reaction using the
mean bond enthalpy data.
(3)
Bond Mean bond enthalpy / kJ mol−1
C C 347
C H 413
C O 358
O H 464
O O 498
C O 805
Enthalpy change = kJ mol−1
..............................................................
*P76895A01228*
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
OD
PMT
(b) (i) Complete the enthalpy cycle for the overall reaction in the Direct Ethanol
Fuel Cell. Include labels.
(2)
Substance Δ H / kJ mol−1
f
C H OH(l) −277
Question
Mathematics
Edexcel2024
5
CO (g) −394
Question
Mathematics
Edexcel2024
H O(l) −286
Question
Mathematics
Edexcel2024
Δ H
r
C H OH(l) + 3O (g) 3H O(l) + 2CO (g)
Question
Mathematics
Edexcel2024
5 2 2 2
(ii) Calculate a value for the enthalpy change of the Direct Ethanol Fuel Cell
reaction, using your cycle.
(1)
Enthalpy change = kJ mol−1
..............................................................
Question
Mathematics
Edexcel2024
5
The equation for the second stage is shown.
SO (g) + ½O (g) SO (g) ΔH = −196 kJ mol−1
Question
Mathematics
Edexcel2024
2 3
(a) (i) What are the expression and the units for the equilibrium constant (K ) for
p
this reaction?
(1)
Expression Units
p(cid:31)SO (cid:30)
A 3 atm2
p(cid:31)SO (cid:30)p(cid:31)O (cid:30)½
Question
Mathematics
Edexcel2024
2
p(cid:31)SO (cid:30)p(cid:31)O (cid:30)½
B 2 2 atm½
p(cid:31)SO (cid:30)
Question
Mathematics
Edexcel2024
2
(ii) Which variable affects the value of K ?
p
(1)
A pressure
B temperature
C surface area of the catalyst
D concentration of O (g)
Question
Mathematics
Edexcel2024
5
State symbols are not required.
(2)
(c) Which row of the table shows the correct colour of the solution and oxidation
number of vanadium in the aqueous ions shown?
(1)
Oxidation number
Aqueous ion Colour of solution
of vanadium
A VO+ yellow +3
Question
Mathematics
Edexcel2024
B VO2+ green +4
C VO+ yellow +5
Question
Mathematics
Edexcel2024
D VO2+ blue +5
(d) What is the value of the cell potential for the reaction of Zn and VO+ ?
Question
Mathematics
Edexcel2024
Use your Data Booklet.
2VO+(aq) + 4H+(aq) + Zn(s) → 2VO2+(aq) + 2H O(l) + Zn2+(aq)
Question
Mathematics
Edexcel2024
2
(1)
A +1.76 V
B +0.24 V
C −0.24 V
D −1.76 V
(Total for Question 7 = 6 marks)
*P76895A01828*
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
OD
PMT
BLANK PAGE
Question
Mathematics
Edexcel2024
C
A
Mg(s) + F (g) MgF (s)
Question
Mathematics
Edexcel2024
2
(ii) Calculate the value of Δ H [MgF (s)].
f 2
(1)
*P76895A02228*
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
OD
PMT
(iii) The experimental and theoretical values of the lattice energy for MgF and
Question
Mathematics
Edexcel2024
MgI are given in the table.
Question
Mathematics
Edexcel2024
Explain the differences in these values.
(4)
Experimental lattice energy Theoretical lattice energy
Compound
/ kJ mol−1 / kJ mol−1
MgF −2957 −2913 2
MgI −2327 −1944 2
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
(Total for Question 8 = 12 marks)
Question
Mathematics
Edexcel2024
2 3
The mean titre was 14.40 cm3 .
2S O2–(aq) + I (aq) → 2I–(aq) + S O2−(aq)
Question
Mathematics
Edexcel2024
3 2 4 6
(i) State the indicator used in this titration, giving the colour change that would
be observed at the end-point.
(2)
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
Question
Mathematics
Edexcel2024
This question is about the formation of ions.
(a) Explain the trend in the values of the first electron affinities of the
elements shown.
(4)
Element First electron affinity / kJ mol−1
chlorine −349
bromine −325
iodine −295
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
(b) Which of these isoelectronic ions has the smallest ionic radius?
(1)
A S2−
B Cl−
C K+
D Ca2+
*P76895A0428*
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
OD
PMT
(c) Some series of successive ionisation energies in kJ mol−1 are shown.
The letters do not refer to the symbols of the elements.
Element Successive ionisation energies / kJ mol−1
A 578 1817 2745 11 578 14 831
B 653 1592 2987 4740 6686
C 738 1451 7733 10 541 13 629
D 1086 2353 4621 6223 37 832
(i) Which element in the table could be in Group 4?
(1)
A
B
C
D
(ii) Which element in the table could be described as an s-block element?
(1)
A
B
C
D
(Total for Question 2 = 7 marks)
Question
Mathematics
Edexcel2024
2 3
V O as the catalyst.
Question
Mathematics
Edexcel2023
appear in the balanced chemical equation for the reaction.
(2)
....................................................................................................................................................................................................................................................................................
Question
Mathematics
Edexcel2017
(i) Give a reason why the partial pressure of carbon is not included in the expression.
(1)
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
(ii) Explain the effect of an increase in pressure on the equilibrium position of this reaction.
(2)
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
(iii) Explain, by reference to any change in the value of K , the effect of an increase
p
in temperature on the equilibrium position of this reaction.
(2)
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
Question
Mathematics
Edexcel2017
2 2
At 1100 K, K = 1.00
c
In an experiment, 1 mol of carbon monoxide was mixed with 1 mol of steam,
Question
Mathematics
Edexcel2017
mol of carbon dioxide and 2 mol of hydrogen.
Deduce, with reasons, the direction in which the reaction will shift to reach equilibrium.
(3)
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
(Total for Question 10 = 12 marks)
TOTAL FOR PAPER = 90 MARKS
*P48058A0228*
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
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
Edexcel2017
Magnesium nitrate decomposes on heating as shown by the equation.
2Mg(NO ) (cid:114) 2MgO + 4NO + O
D Mn 2+(aq)
(ii) Write the ionic equation and calculate the E value for the reaction between
cell
MnO– ions and Br – ions in acidic solution.
Question
Mathematics
Edexcel2017
6 2 6
form a colourless solution.
Explain why zinc ions are colourless.
(2)
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................................................................
(c) Hydrated iron(II) ions react with ethanedioate ions, C O2–, to form a complex ion.
Question
Mathematics
Edexcel2017
4
[Fe(H O) ]2+ + 2C O2– (cid:85) [Fe(C O ) (H O) ]2– + 4H O
Question
Mathematics
Edexcel2017
6 2 4 2 4 2 2 2 2
(i) Draw a structure of the [Fe(C O ) (H O) ]2– ion, showing all of the bonds.
Question
Mathematics
Edexcel2017
4 2 2 2
(2)
Question
Mathematics
Edexcel2017
8
2I–(aq) + S O2–(aq) (cid:114) I (aq) + 2SO2–(aq)
Question
Mathematics
Edexcel2017
8 2 4
This reaction is catalysed by iron(II) ions, Fe2+(aq).
Write two ionic equations to show how iron(II) ions act as a catalyst in this reaction.
State symbols are not required.
(2)
(Total for Question 4 = 9 marks)