Setting chemistry Exam Education Coursework Paper Essay (Coursework Sample)

NAME………………………………………………ADM.NO:………………CLASS………..……..
CHEMISTRY
FORM 2
END OF TERM 2 EXAM - 2020
TIME: 2 HOURS
INSTRUCTIONS TO STUDENTS
1.Answer all questions in this question paper.
2.All your answers must be written in the spaces provided in this question paper.
Question

Maximum score

Candidates score

1-15

70


1. Define the following terms:
* Atomic Number (2mk)
* Mass Number (2mk)
* The Isotopes (2mk)
1 685800371475Oxygen is obtained on large scale by the fractional distillation of air as shown on the flow chart below.
a) Explain why air is considered as a mixture(1mk)
b) Identify the substance that is removed at the filtration stage(1mk)
c) Explain why Carbon (IV) oxide and water are removed before liquefaction of air.(1mk)
d) Identify the component that is collected at -186°C (1mk)
2 Study the table below and answer the questions that follow:-
Substance
Melting Point (oC )
Boiling point (oC)

A

B

C

D

E

F


801

113 OR 119

-39

5

-101

1356


1410

445

457

54

-36

2860

Electrical
Conductivity

Solid

Poor

Poor

Good

Poor

Poor

Poor


liquid

Good

Poor

Good

Poor

Poor

Poor

Identify with reasons the substances that:
(i) Have a metallic structure(2mks)
(ii) Have a molecular structure(2mks)
(iii) Substances A and C conduct electric current in the liquid state. State how the two
substances differ as conductors of electric current(2mks)
3 Atoms of element X exists as 146X and 126X
(a) What name is given to the two types of atoms.(1mk)
………………………………………………………………………………………………………
(b) Use dot (∙) and cross (x) diagrams to illustrate the atomic structure of 146X (2mks) ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
4 Give two reasons why most laboratory apparatus are made of glass.(2mk)
6 . Define the following terms:
* A saturated solution. (2mk)
* Crystallization. (2mk)
1 Describe how copper (II) sulphate crystals can be obtained from copper (II) sulphate solution. (3mks)
2 Study the table below and use it to answer the questions that follows. Letters are not the actual symbols of the elements
Ion

Electronic configuration

L-

2,8,8

M2+

2,8

N3+

2,8,8

* Which elements belong to the same period of the periodic table? (1 mark)
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* What is the formula of the compound formed by L and N.? (1 mark)
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* Compare the atomic and ionic radii of element L. (1 mark)
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3 Write the chemical fomular of the following compounds. 3mks
* Sodium sulphate
* Magnesium hydroxide
* Calcium nitrate.
4 State the reasons why carbon ( iv) oxide is used by ice cream venders instead of ordinary ice.(2mks)
5 A student set-up the apparatus below in order to determine the percentage by volume of oxygen in air.
AT ENDAT BEGINING