Reg. No:…………………………….
KIGALI INSTITUTE OF SCIENCE AND TECHNOLOGY
INSTITUT DES SCIENCES ET TECHNOLOGIE
Avenue de l'Armée, B.P. 3900 Kigali, Rwanda
INSTITUTE EXAMINATIONS – ACADEMIC YEAR 2013
END OF YEAR EXAMINATION
FACULTY OF SCIENCE
SCIENCE 4-CHEMISTRY
FIRST YEAR, SUPLEMENTARY EXAM SEM. II
CHE 3122-INORGANIC CHEMISTRY I
DATE: 24/06/2013
TIME: 2 HOURS
MAXIMUM MARKS = 60
INSTRUCTIONS
1.
2.
3.
4.
5.
6.
7.
This paper contains Two (2) sections
Answer question One in section A and any Two in section B
First question is compulsory
No written materials allowed.
Write all answers in the booklet provided.
Do not forget to write your Registration Number.
Do not write any answers on this question paper
SECTION A
1.
i) What is the main source of boron? Outline the steps in the extraction
of boron.
ii) Characterize briefly the chemical properties of group IA element
(4marks)
(4marks)
iii) What are the most common oxidation states of carbon and tin? Explain the
difference?
(4marks)
iv) Review the use of Fluorine
(4marks)
v) Explain the process of photosynthesis by which the oxygen has been
produced
(4marks)
SECTION B
2.
a) How does diborane react with
i) ammonia,
(2marks)
ii) boron tribromide and
(2marks)
iii) trimethyl boron ?
(2marks)
b) i) Outline the reactions that take place in hydrogen manufacturing from natural
gas(methane)
(4marks)
ii) Explain why the melting point boiling point in group I and group II decrease down
the group and increase down the group in halogens group.
(4marks)
c) i) Draw the structures of diamond and graphite,
ii) explain the difference in density between diamond and graphite,
iii) Explain the difference in electrical conductivity between diamond and graphite,
iv) Which allotropic form of C has the lowest energy?
3.
(6marks)
a) i). Explain the paramagnetic character for dioxygen using the molecular orbital
theory
(5marks)
ii). Give all oxidation states with the compound corresponding for nitrogen (5marks)
iii) Explain the availabilities of the orbital for getting the xenon compounds as
XeF2, XeF4 and XeF6
,
Give their composition ratios
(5marks)
b) i) List as many ways as possible the preparation of CO and CO2.
ii) What are they used for?
(5marks)
4.
a) i) How would you define a transition element? List the properties associated with
transition element
ii) Suggest reasons why PF5 exist but NF5 is not.
iii) Give the formulae of 11 interhalogen compounds,
(5marks)
(4 marks)
(4 marks)
b) How do the following properties vary in the transition element:
i ) ionic character
ii) basic properties
(2marks)
c) In which ways does the filling of the 4f energy level affect the rest of the periodic
table?
(5marks)
Good Luck!!!!!