2021 Chemistry Ocr A level. Paper 1 QP
CANDIDATE
NAME
CIVICS INDEX
GROUP
2 0 – NUMBER
CHEMISTRY 9813/01
Paper 1
23 September 2021
2 hours 30 minutes
Candidates answer on Question Paper.
Additional Materials: Data Booklet
Insert
READ THESE INSTRUCTIONS FIRST
Write your name, civics group and registration number on all the work you hand in.
Write in dark blue or black pen.
You may use an HB pencil for any diagrams or graphs.
Do not use staplers, paper clips, glue or correction fluid.
For Examiner’s Use
Answer all questions in the spaces provided on the Question Paper. If
Section A
additional space is required, you should use the pages at the end of this
booklet. The question number must be clearly shown. 1 / 20
Section A 2 / 11
Answer all questions.
3 / 10
Section B
4 / 19
Answer two questions.
Section B
The use of an approved scientific calculator is expected, where
appropriate. 5 / 20
A Data Booklet is provided.
6 / 20
At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question 7 / 20
or part question.
Total / 100
This document consists of 35 printed pages and 1 blank page.
© EJC [Turn Over
, 2
Section A
Answer all the questions in this section.
1 The information provided in the insert is taken from several published scientific
articles. Other published articles may not agree with all of this information.
You should read the whole insert before you start to answer any questions and use
the information it contains to answer the questions.
(a) (i) Write an equation for the main reaction in the carbonator, including state symbols.
[1]
(ii) Suggest a likely source for the calcium carbonate input. [1]
(iii) Besides CO2, suggest the identity of two other gases which are likely to be the
main constituent of flue gases. [1]
(iv) With reference to your answer to (a)(iii), suggest the principle component of
Gas Y exiting from the carbonator. [1]
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(b) One of the impurities in flue gases is sulfur dioxide from the combustion of sulfur-
containing fuels. This can react in the carbonator to form calcium sulfate, which can
accumulate over successive cycles and reduce the efficiency of the process.
(i) Write an equation for the reaction of sulfur dioxide with calcium carbonate and
oxygen to give two products, of which one is calcium sulfate. [1]
(ii) By comparing the thermal stability of calcium sulfate and calcium carbonate,
explain why calcium sulfate accumulates over successive cycles. [3]
(iii) Name another impurity in flue gases and explain how this impurity comes about.
[2]
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© EJC 9813/01/J2PE/21 [Turn Over
, 4
(c) Direct air capture (DAC) is a process which takes carbon dioxide directly from the air
therefore avoiding any sulfur dioxide contamination. However, this process can be
expensive to run due to the energy required to overcome thermodynamic barriers.
(i) Besides avoiding sulfur dioxide contamination, state the main difference between
using flue gas and air as the source of CO2. [1]
(ii) Write an equation, including state symbols, for the reaction in the
air contactor
pellet reactor. [2]
(iii) Water is consumed in the slaker, but the demand for water is balanced in the
overall process. Use your answer to (c)(ii) to explain why this is so. [1]
(iv) Use your answer to (c)(ii) and the standard enthalpy change of formation data
at 298 K given below, calculate the standard enthalpy change for the reaction
which occurs in the air contactor.
□ 1
compound Hf kJ mol
CaO(s) –634.9
CaCO3(s) –1207.6
Ca(OH)2(s) –985.2
KOH(aq) –482.4
K2CO3(aq) –1181.9
CO2(g) –393.5
H2O(l) –285.8
[2]
(v) What is the standard enthalpy change at 298 K for the sum of the reactions in
the four reactors. Explain your answer. [2]
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© EJC 9813/01/J2PE/21
CANDIDATE
NAME
CIVICS INDEX
GROUP
2 0 – NUMBER
CHEMISTRY 9813/01
Paper 1
23 September 2021
2 hours 30 minutes
Candidates answer on Question Paper.
Additional Materials: Data Booklet
Insert
READ THESE INSTRUCTIONS FIRST
Write your name, civics group and registration number on all the work you hand in.
Write in dark blue or black pen.
You may use an HB pencil for any diagrams or graphs.
Do not use staplers, paper clips, glue or correction fluid.
For Examiner’s Use
Answer all questions in the spaces provided on the Question Paper. If
Section A
additional space is required, you should use the pages at the end of this
booklet. The question number must be clearly shown. 1 / 20
Section A 2 / 11
Answer all questions.
3 / 10
Section B
4 / 19
Answer two questions.
Section B
The use of an approved scientific calculator is expected, where
appropriate. 5 / 20
A Data Booklet is provided.
6 / 20
At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question 7 / 20
or part question.
Total / 100
This document consists of 35 printed pages and 1 blank page.
© EJC [Turn Over
, 2
Section A
Answer all the questions in this section.
1 The information provided in the insert is taken from several published scientific
articles. Other published articles may not agree with all of this information.
You should read the whole insert before you start to answer any questions and use
the information it contains to answer the questions.
(a) (i) Write an equation for the main reaction in the carbonator, including state symbols.
[1]
(ii) Suggest a likely source for the calcium carbonate input. [1]
(iii) Besides CO2, suggest the identity of two other gases which are likely to be the
main constituent of flue gases. [1]
(iv) With reference to your answer to (a)(iii), suggest the principle component of
Gas Y exiting from the carbonator. [1]
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
© EJC 9813/01/J2PE/21
, 3
(b) One of the impurities in flue gases is sulfur dioxide from the combustion of sulfur-
containing fuels. This can react in the carbonator to form calcium sulfate, which can
accumulate over successive cycles and reduce the efficiency of the process.
(i) Write an equation for the reaction of sulfur dioxide with calcium carbonate and
oxygen to give two products, of which one is calcium sulfate. [1]
(ii) By comparing the thermal stability of calcium sulfate and calcium carbonate,
explain why calcium sulfate accumulates over successive cycles. [3]
(iii) Name another impurity in flue gases and explain how this impurity comes about.
[2]
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
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...........................................................................................................................
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© EJC 9813/01/J2PE/21 [Turn Over
, 4
(c) Direct air capture (DAC) is a process which takes carbon dioxide directly from the air
therefore avoiding any sulfur dioxide contamination. However, this process can be
expensive to run due to the energy required to overcome thermodynamic barriers.
(i) Besides avoiding sulfur dioxide contamination, state the main difference between
using flue gas and air as the source of CO2. [1]
(ii) Write an equation, including state symbols, for the reaction in the
air contactor
pellet reactor. [2]
(iii) Water is consumed in the slaker, but the demand for water is balanced in the
overall process. Use your answer to (c)(ii) to explain why this is so. [1]
(iv) Use your answer to (c)(ii) and the standard enthalpy change of formation data
at 298 K given below, calculate the standard enthalpy change for the reaction
which occurs in the air contactor.
□ 1
compound Hf kJ mol
CaO(s) –634.9
CaCO3(s) –1207.6
Ca(OH)2(s) –985.2
KOH(aq) –482.4
K2CO3(aq) –1181.9
CO2(g) –393.5
H2O(l) –285.8
[2]
(v) What is the standard enthalpy change at 298 K for the sum of the reactions in
the four reactors. Explain your answer. [2]
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
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© EJC 9813/01/J2PE/21
