NAME…………………………………………………….. CLASS ………HOUSE................
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CHEMISTRY
PAPER 2
(THEORY)
November, 2022
2 HOURS
THE KENYA HIGH SCHOOL
FORM TWO END YEAR EXAM
CHEMISTRY
PAPER 2
(THEORY)
2 HOURS
Instructions to candidates:
Write your name, class and House in the spaces provided above.
Answer ALL the questions in the spaces provided.
Electronic calculators and Mathematical table may be used.
All working must be clearly shown where necessary.
For examiner’s use only:
Question Maximum Student’s
Score Score
1 15
2 12
3 11
4 13
5 16
6 14
Total Score 80
This paper consists of 12 printed pages.
Students should check to ascertain that all the pages are printed
as indicated and that no questions are missing.
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1. (a) Name two sub-atomic particles found in the nucleus of an atom. (2
marks)
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(b) I. What is isotope? (1 mark)
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II. Element P has two isotopes 60 and 61 which occur in the ratio X:2.
Given that
its R.A.M is 60.4. Calculate the value of X (3
marks)
(c) Element J has mass number 40 and 21 neutrons
i. Determines the atomic number. (1
mark)
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ii. Write electron arrangement of element J. (1 mark)
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iii. Draw the structure of the atom, showing the composition of the nucleus. (2
marks)
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(d) i. What is Radical? (1 mark)
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ii. Give the radicals of Sulphur and carbonate, then write the formula of their
salts of
copper. (4 marks)
element Formula of Formula of salt of
radical copper
Nitrogen NO3 Cu(NO3)2
Sulphur
Carbon
2. I. Define the following terms; (2 marks)
(i) Electrolysis
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(ii) Electrolyte
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II. The set up below was used to investigate the effect of an electric current on
molten lead (II) bromide.
(a) Identify the anode and cathode on the diagram. (2 marks)
(b) State what is observed at the: (2
marks)
(i) Cathode
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(ii) Anode
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(c) Write equations for the reactions at the: (2 marks)
(i) Cathode
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(ii) Anode
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(d) State a precaution that should be taken when carrying out this experiment.
(1 mark)
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(e) Give two applications of electrolysis. (2
marks)
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3. The set up below was used to collect gas F produced by the reaction between
water and calcium metal
(i) Name gas F. (1
mark)
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(ii) State two observations made when calcium react with water. (2
marks)
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(iii)Write an equation for the reaction between calcium and water. (1
mark)
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(iv) Give one laboratory use of the solution formed in a beaker. (1
mark)
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(v) Explain why potassium metal cannot be used in the above experiment. (1
mark)
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(b) When hydrogen gas is passed over heated lead (ii) oxide, a reaction occurs as
shown in the set-up below.
(i) State and explain the observation made in the combustion tube. (2
marks)
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(ii) Explain why hydrogen was passed through the combustion tube before heating.
(1mark)
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(iii) Give property of hydrogen demonstrated in the above experiment.
(1 mark)
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(iv) State two commercial uses of hydrogen gas. (2
marks)
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4. The grid given below represents part of the periodic table. Study it and answer
the questions that follow. (The letters do not represent the actual symbol of the
elements)
J
A C D E H
F Z P
(i) What name is given to the group of elements to which H and P belong? (1
mark)
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(ii) Which letter represents the element that is the most reactive metal?
(1 mark)
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(iii) What type of bond is formed when C and H react? (1 mark)
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(iv) Write an equation when element D and oxygen gas react. (1 mark)
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(v) On the grid, indicate with a tick (✓) the position of element G which is in the
third period of the periodic table and forms G3- ions.
(1 mark)
(vi) Which is the most reactive non-metallic element? Explain. (2 marks)
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(vii) Compare the atomic radius of C and D, giving reason for your answer. (2
marks)
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(b) The table below gives some properties of substances of A, B, C and D. study it and
answer the questions that follow.
Substance Electrical conductivity M.P B.P
Solid Molten (0C) (0C)
A Does on conduct 801 1420
conduct
B conduct conduct 650 1107
C Does on Does on conduct 1700 2200
conduct
D Does on Does on conduct 113 440
conduct
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(i) What type of bonding exists in substances A and B? (2
marks)
A…………………………………………………………………………………
B…………………………………………………………………………………
(ii) Which substance is likely to be Sulphur? Explain. (2 marks)
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5. I. Study the flow chart below and answer the questions that follow
Step 1
Yellow solid B Brown fumes C
White solid A
when cold
+ + colourless gas
D
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Step 2 Dilute nitric (V) acid
Salt solution Add dil. H2SO4
White precipitate
E and water F
5. Give the name of the process that take place in: (2
marks)
Step 1…………………………………………………………………….
Step 2…………………………………………………………………….
b) Identify the following: (3
marks)
White solid A
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Brown fumes C
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Salt solution E
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(c) Write an equation for the reaction between solid B and dilute nitric (v) acid (1
mark)
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(d) Write an ionic equation for formation of white precipitate F. (1
mark)
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II. Below is a brief outline of a method used in preparing the lead (II) nitrate crystals.
Measure about 25 cm3 of dilute nitric (V) acid into a glass beaker and warm it.
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Add excess of lead (II) carbonate into the acid and stir. Filter the mixture and pour the
filtrate into an evaporating basin. Heat the filtrate over a water bath to saturation. Stop
heating and allow the saturated solution to cool to form crystals. Pour out mother liquor.
Dry the crystals between filter papers.
(a) Why is;
(i) Nitric (V) acid warmed before adding the carbonate? (1
mark)
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(ii) Lead (II) carbonate added in excess into the acid? (1
mark)
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(iii) Filtration process is necessary in salt preparation? (1
mark)
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(b) State the observation made when Lead (II) carbonate is added to Nitric (V) acid.
(1 mark)
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(c) Write an equation for the reaction between Lead (II) carbonate and Nitric (V) acid.
(1 mark)
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III. Using the following reagents describe briefly how pure solid lead (II) Sulphate can be
prepared in the laboratory: (4
marks)
Solid sodium sulphate, solid lead (II) Carbonate, distilled water, dilutes nitric (V) acid.
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6. (a) Using dot (.)and cross (x) diagram, show bonding in: (5
marks)
(N -7, H – 1, O – 8, Mg – 12, CI – 17, C - 6)
(i) Ammonia, NH3 (ii) Hydroxonium ion, (H3O+)
(iii) Magnesium chloride, MgCl2 (iv) Methane, CH4
(b) Carbon has two allotropes
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(i) What is an allotrope? (1 mark)
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(ii) Name two allotropes of carbon. (2
marks)
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(iii)One of the allotropes is used for drilling bits. Identify the allotrope,
giving a reason. (2
marks)
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(c) Explain the following observations;
(i) Sulphur has a higher boiling point than oxygen gas. (2 marks)
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(ii) Magnesium chloride has a higher melting point than phosphorus (III)
chloride. (2 marks)
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