lOMoARcPSD|54878315
UNIVERSITY EXAMINATIONS
OCTOBER/NOVEMBER 2025
CHE2611
INORGANIC CHEMISTRY II (THEORY)
Welcome to the CHE2611 examination
Date: 14 October 2025
Time: 10:45 – 13:45
Hours: 3 hours
Examiner name: Mr KC Tapala
Internal moderator name: Ms NH Zulu
This paper consists of 10 pages.
Total marks: 100
Number of pages: 10
Instructions:
• This is a CLOSED BOOK EXAMINATION.
• This examination paper contains FOUR questions.
• Use of a non-programmable SCIENTIFIC calculator is permissible.
• You should attempt to answer all questions.
• Start each question on a new page.
• Show all mathematical formulae used in calculations.
• Show all units in calculations, as marks will be deducted for wrong or missing units.
SUPPLEMENTARY INFORMATION
The Periodic Table and Supplementary Information are provided in Appendix A.
Appendix B provides instructions on submitting the file with answers.
Honesty Declaration is mandatory.
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CONFIDENTIAL CHE2611
October/November 2025
A student who is guilty of the infringement of copyright or unethical practice, or
who received aid on this Assessment, will be subject to the applicable disciplinary
code.
Internet connectivity is mandatory during the entire examination.
CHE2611 Exam is IRIS invigilated.
HOW DO I UPLOAD MY EXAMINATION ANSWER FILE?
1. Access myExams at https://cset.myexams.unisa.ac.za and login using your student
number and myUnisa password.
2. Go to the “CHE2611 Exam Oct/Nov 2025” site through the site tabs on the horizontal
navigation bar. Also check your Sites link in the top right-hand corner if you do not find the
site on the horizontal navigation bar.
3. Once the site has loaded, select the eAssessment tool from the left navigation menu.
4. The list of all available assessments on the site will be displayed
5. Select the "CHE2611 Examination" in the assessment list. A new page will open.
6. Click the honour pledge.
7. Submit your examination answer file.
Additional student instructions
1. Students must upload their answer scripts in a single PDF file (answer scripts must not be
password protected or uploaded as “read only” files)
2. Incorrect file format and uncollated answer scripts will not be considered.
3. NO emailed scripts will be accepted.
4. Students are advised to preview submissions (answer scripts) to ensure legibility and that
the correct answer script file has been uploaded.
5. Incorrect answer scripts and/or submissions made on unofficial examinations platforms
(including the invigilator cell phone application) will not be marked and no opportunity will
be granted for resubmission. Only the last answer file uploaded within the stipulated
submission duration period will be marked.
6. Mark awarded for incomplete submission will be the student’s final mark. No opportunity for
resubmission will be granted.
7. Mark awarded for illegible scanned submission will be the student’s final mark. No
opportunity for resubmission will be granted.
8. Submissions will only be accepted from registered student accounts.
9. Students who have not utilised the proctoring tool will be deemed to have transgressed
Unisa’s examination rules and will have their marks withheld. If a student is found to have
been outside the proctoring tool for a total of 10 minutes during their examination session,
they will be considered to have violated Unisa’s examination rules and their marks will be
withheld. For examinations which use the IRIS invigilator system, IRIS must be recording
throughout the duration of the examination until the submission of the examinations scripts.
Page 2 of 10
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CONFIDENTIAL CHE2611
October/November 2025
10. Students have 48 hours from the date of their examination to upload their invigilator results
from IRIS. Failure to do so will result in students deemed not to have utilized the proctoring
tools.
11. Students suspected of dishonest conduct during the examinations will be subjected to
disciplinary processes. Students may not communicate with any other person or request
assistance from any other person during their examinations. Plagiarism is a violation of
academic integrity and students who plagiarise, copy from published work or Artificial
Intelligence Software (eg ChatGPT) or online sources (eg course material), will be in
violation of the Policy on Academic Integrity and the Student Disciplinary Code and may be
referred to a disciplinary hearing. Unisa has a zero tolerance for plagiarism and/or any
other forms of academic dishonesty.
12. Listening to audio (music) and making use of audio-to-text software is strictly prohibited
during your examination session unless such usage of the software is related to a student’s
assistive device which has been so declared. Failure to do so will be a transgression of
Unisa’s examination rules and the student's marks will be withheld.
13. Students are provided 30 minutes to submit their answer scripts after the official
examination time. Students who experience technical challenges should report the
challenges to the SCSC on 080 000 1870 or their College exam support centres (refer to
the Get help during the examinations by contacting the Student Communication Service
Centre [unisa.ac.za]) within 30 minutes. Queries received after 30 minutes of the official
assessment duration time will not be responded to. Submissions made after the official
assessment time will be rejected according to the examination regulations and will not be
marked. Only communication received from your myLife account will be considered.
14. Non-adherence to the processes for uploading assessment responses will not qualify the
student for any special concessions or future assessments.
15. Queries that are beyond Unisa’s control include the following: a. Personal network or
service provider issues
b. Load shedding/limited space on personal computer
c. Crashed computer
d. Non-functioning cameras or web cameras
e. Using work computers that block access to the myExams site (employer firewall
challenges)
f. Unlicensed software (eg license expires during exams)
Postgraduate students experiencing the above challenges are advised to apply for an
aegrotat and submit supporting evidence within ten days of the examination session.
Students will not be able to apply for an aegrotat for a third examination opportunity.
Postgraduate/undergraduate students experiencing the above challenges in their second
examination opportunity will have to reregister for the affected module.
16. Students suspected of dishonest conduct during the examinations will be subjected to
disciplinary processes. UNISA has a zero tolerance for plagiarism and/or any other forms
of academic dishonesty.
17. Students experiencing network or load shedding challenges are advised to apply together
with supporting evidence for an Aegrotat within 3 days of the examination session.
Page 3 of 10
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CONFIDENTIAL CHE2611
October/November 2025
QUESTIONS
Question 1
Define the following terms and illustrate your answer with a suitable example.
(a) Geometric isomer
(b) Hydroxo acid
(c) Optical isomerism
(d) Polydentate ligand
(e) Linkage isomerism
(f) Ambidentate ligand
(g) Amphiprotic species
(h) Lewis base
(i) Coordination isomerism
(j) Aqua acid
(15)
[15 marks]
Question 2
(a) What are ionic solids?
(2)
(b) Describe the four general trends in ionic radii.
(8)
(c) Write down the Born-Mayer equation and identify each of its terms.
(10)
(d) Write down the Kapustinskii equation and describe each of the terms.
(10)
(e) Explain why the two equations above exhibit some discrepancies when
compared to the values obtained from the Born-Haber cycle.
(5)
[35 marks]
Question 3
(a) Rank the three Lewis acids in terms of increasing acid strength: B(CH3)3, BCl3
and BH3. Motivate your answer.
(5)
Page 4 of 10
Downloaded by Stephen ()
UNIVERSITY EXAMINATIONS
OCTOBER/NOVEMBER 2025
CHE2611
INORGANIC CHEMISTRY II (THEORY)
Welcome to the CHE2611 examination
Date: 14 October 2025
Time: 10:45 – 13:45
Hours: 3 hours
Examiner name: Mr KC Tapala
Internal moderator name: Ms NH Zulu
This paper consists of 10 pages.
Total marks: 100
Number of pages: 10
Instructions:
• This is a CLOSED BOOK EXAMINATION.
• This examination paper contains FOUR questions.
• Use of a non-programmable SCIENTIFIC calculator is permissible.
• You should attempt to answer all questions.
• Start each question on a new page.
• Show all mathematical formulae used in calculations.
• Show all units in calculations, as marks will be deducted for wrong or missing units.
SUPPLEMENTARY INFORMATION
The Periodic Table and Supplementary Information are provided in Appendix A.
Appendix B provides instructions on submitting the file with answers.
Honesty Declaration is mandatory.
Downloaded by Stephen ()
, lOMoARcPSD|54878315
CONFIDENTIAL CHE2611
October/November 2025
A student who is guilty of the infringement of copyright or unethical practice, or
who received aid on this Assessment, will be subject to the applicable disciplinary
code.
Internet connectivity is mandatory during the entire examination.
CHE2611 Exam is IRIS invigilated.
HOW DO I UPLOAD MY EXAMINATION ANSWER FILE?
1. Access myExams at https://cset.myexams.unisa.ac.za and login using your student
number and myUnisa password.
2. Go to the “CHE2611 Exam Oct/Nov 2025” site through the site tabs on the horizontal
navigation bar. Also check your Sites link in the top right-hand corner if you do not find the
site on the horizontal navigation bar.
3. Once the site has loaded, select the eAssessment tool from the left navigation menu.
4. The list of all available assessments on the site will be displayed
5. Select the "CHE2611 Examination" in the assessment list. A new page will open.
6. Click the honour pledge.
7. Submit your examination answer file.
Additional student instructions
1. Students must upload their answer scripts in a single PDF file (answer scripts must not be
password protected or uploaded as “read only” files)
2. Incorrect file format and uncollated answer scripts will not be considered.
3. NO emailed scripts will be accepted.
4. Students are advised to preview submissions (answer scripts) to ensure legibility and that
the correct answer script file has been uploaded.
5. Incorrect answer scripts and/or submissions made on unofficial examinations platforms
(including the invigilator cell phone application) will not be marked and no opportunity will
be granted for resubmission. Only the last answer file uploaded within the stipulated
submission duration period will be marked.
6. Mark awarded for incomplete submission will be the student’s final mark. No opportunity for
resubmission will be granted.
7. Mark awarded for illegible scanned submission will be the student’s final mark. No
opportunity for resubmission will be granted.
8. Submissions will only be accepted from registered student accounts.
9. Students who have not utilised the proctoring tool will be deemed to have transgressed
Unisa’s examination rules and will have their marks withheld. If a student is found to have
been outside the proctoring tool for a total of 10 minutes during their examination session,
they will be considered to have violated Unisa’s examination rules and their marks will be
withheld. For examinations which use the IRIS invigilator system, IRIS must be recording
throughout the duration of the examination until the submission of the examinations scripts.
Page 2 of 10
Downloaded by Stephen ()
, lOMoARcPSD|54878315
CONFIDENTIAL CHE2611
October/November 2025
10. Students have 48 hours from the date of their examination to upload their invigilator results
from IRIS. Failure to do so will result in students deemed not to have utilized the proctoring
tools.
11. Students suspected of dishonest conduct during the examinations will be subjected to
disciplinary processes. Students may not communicate with any other person or request
assistance from any other person during their examinations. Plagiarism is a violation of
academic integrity and students who plagiarise, copy from published work or Artificial
Intelligence Software (eg ChatGPT) or online sources (eg course material), will be in
violation of the Policy on Academic Integrity and the Student Disciplinary Code and may be
referred to a disciplinary hearing. Unisa has a zero tolerance for plagiarism and/or any
other forms of academic dishonesty.
12. Listening to audio (music) and making use of audio-to-text software is strictly prohibited
during your examination session unless such usage of the software is related to a student’s
assistive device which has been so declared. Failure to do so will be a transgression of
Unisa’s examination rules and the student's marks will be withheld.
13. Students are provided 30 minutes to submit their answer scripts after the official
examination time. Students who experience technical challenges should report the
challenges to the SCSC on 080 000 1870 or their College exam support centres (refer to
the Get help during the examinations by contacting the Student Communication Service
Centre [unisa.ac.za]) within 30 minutes. Queries received after 30 minutes of the official
assessment duration time will not be responded to. Submissions made after the official
assessment time will be rejected according to the examination regulations and will not be
marked. Only communication received from your myLife account will be considered.
14. Non-adherence to the processes for uploading assessment responses will not qualify the
student for any special concessions or future assessments.
15. Queries that are beyond Unisa’s control include the following: a. Personal network or
service provider issues
b. Load shedding/limited space on personal computer
c. Crashed computer
d. Non-functioning cameras or web cameras
e. Using work computers that block access to the myExams site (employer firewall
challenges)
f. Unlicensed software (eg license expires during exams)
Postgraduate students experiencing the above challenges are advised to apply for an
aegrotat and submit supporting evidence within ten days of the examination session.
Students will not be able to apply for an aegrotat for a third examination opportunity.
Postgraduate/undergraduate students experiencing the above challenges in their second
examination opportunity will have to reregister for the affected module.
16. Students suspected of dishonest conduct during the examinations will be subjected to
disciplinary processes. UNISA has a zero tolerance for plagiarism and/or any other forms
of academic dishonesty.
17. Students experiencing network or load shedding challenges are advised to apply together
with supporting evidence for an Aegrotat within 3 days of the examination session.
Page 3 of 10
Downloaded by Stephen ()
, lOMoARcPSD|54878315
CONFIDENTIAL CHE2611
October/November 2025
QUESTIONS
Question 1
Define the following terms and illustrate your answer with a suitable example.
(a) Geometric isomer
(b) Hydroxo acid
(c) Optical isomerism
(d) Polydentate ligand
(e) Linkage isomerism
(f) Ambidentate ligand
(g) Amphiprotic species
(h) Lewis base
(i) Coordination isomerism
(j) Aqua acid
(15)
[15 marks]
Question 2
(a) What are ionic solids?
(2)
(b) Describe the four general trends in ionic radii.
(8)
(c) Write down the Born-Mayer equation and identify each of its terms.
(10)
(d) Write down the Kapustinskii equation and describe each of the terms.
(10)
(e) Explain why the two equations above exhibit some discrepancies when
compared to the values obtained from the Born-Haber cycle.
(5)
[35 marks]
Question 3
(a) Rank the three Lewis acids in terms of increasing acid strength: B(CH3)3, BCl3
and BH3. Motivate your answer.
(5)
Page 4 of 10
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