CHEMISTRY FORM 3 END TERM EXAMS PLUS ANSWERS IN PDF
ULTIMATE ACHIEVERS ACADEMY
Name___________________________________________________AdmNo:_____________
Date__________________________________________Sign______________
END OF TERM EXAMINATION
FORM THREE
CHEMISTRY
2 HOURS
Instructions to candidates:
- Answer all questions in both section A and B.
- All working must be clearly shown and, in the spaces provided.
FOR EXAMINER’S USE ONLY
Section | Maximum
Score |
Candidate’s
Score |
A | 40 | |
B | 40 | |
Grand Score | 80 |
SECTION A 40MARKS
- Distinguish between an element and a compound. (2 Mks)
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- A compound has an empirical formula of C2H5 Given it has a R.M.M. of 90, determine its molecular formulae. (C=12, H=1, O=16) (2 Mks)
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- Identify the particles responsible for electrical conductivity in each of the following. (3 Mks)
- Molten sodium chloride
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- Zinc metal
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- Graphite
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- The diagram below shows a set up used to investigate one of the conditions necessary for rusting.
- Identify the conditions being investigated in the experiment. (1 Mk)
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- State whether rusting occurred or Not. (1 Mk)
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- Explain why rusting occurs faster near factories that emit gases such as CO2, NO2 and SO2 into the atmosphere. (2 Mks)
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- Explain why a reaction occurs between copper (ii) oxide and magnesium powder, but no reaction occurs between magnesium oxide and copper powder. (2 Mks)
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- The set-up below shows one of the methods used to separate a mixture of liquids P and Q
- State two properties of the liquids P and Q that make it possible to separate using the above method. (2 Mks)
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- Name any other two methods that can be used to separate the mixture of liquids p and Q.
(2 mks)
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- The diagram below shows arrangement of particles in the three state of matter in no particular order.
- Which of the diagrams I, II and III represents;
- Matter in the solid state. (1 Mks)
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- Matter in the gaseous state. (1 Mk)
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- State in which matter has the highest kinetic energy. (1 Mk)
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- The ratio of the rates if diffusion of gas X and gas y is 3:8. Given that 200 cm3of gas X diffuse through a porous plug in 75 seconds. How long would it take 160 cm3 of gas Y to diffuse under the same conditions? (3 Mks)
- Describe how you can prepare a dry sample of barium sulphate starting with Barium nitrate crystals. (3 Mks)
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- Sodium carbonate can be obtained on large scale by manufacturing through the Solvay process.
- Name two raw materials for this process. (2 Mks)
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- Identify any other method that can be used to obtain sodium carbonate on large scale.
(1 Mk)
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- State one use of sodium carbonate. (1 Mk)
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- Molten lead (ii) bromide was electrolyzed using carbon electrodes.
- Name any other substance that can suitably be used as electrodes in place of carbon. (1 Mk)
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- Name the product formed at the cathode. (1 Mk)
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- Write the ionic equation of the reaction that occurred at the cathode. (1 Mk)
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- The diagram below shows parts of a set-up to prepare and collect dry hydrogen gas.
- Identify reagent N and drying agent K. (2 Mks)
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- Complete the diagram to show how the dry hydrogen gas is collected. (2 Mks)
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- Using universal indicator, describe how you can determine the PH value of a given solution.
(2 Mks)
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- State one advantage of universal indicator over other commercial indicators. (1 Mk)
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SECTION B
- The grid below shows a section of the periodic table, the letters are not the actual chemical symbols.
- Name the family into which element Q belongs to (1 Mk)
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- Element E can be placed in group I or group VII. Explain why (2 Mks)
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- What Name is given to the elements found in the shaded region W. (1 Mk)
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- Which letter represents element with the highest melting point in group II. Give reasons
(2 Mks)
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- Write the chemical formulae of the;
- Sulphate of L (1 Mk)
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- Nitrate of R (1 Mk)
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- How does the following compare? Explain your answer
- Reactivity of J and N. (2 Mks)
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- Boilling point of the oxides of M and T. (2 Mks)
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- In an experiment, 80 cm3 of 0.75 M hydrochloride acid were reacted with excess zinc carbonate to form solution W, Liquid R and gas T.
- Identify solution W and gas T. (2 Mks)
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- Write a chemical equation of the reaction that occurred. (1 Mk)
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- Calculate the;
- Number of moles of hydrochloric acid that reacted with the zinc carbonate. ( 2 Mks)
- Number of moles of the Zinc carbonate that reacted with the acid (2 Mks)
- Mass of the Zinc carbonate that reacted with the acid. (Zn = 65, C= 12, O= 16)
(2 Mks)
- Volume of gas T evolved at r.t.p. (1 Mole of gas at r.t.p. = 24 litres) (2 Mks)
- (a). Name the following hydrocarbons (3Mks)
- CH3CH2CH2CH2CH3 ______________________________________
- CH3CHCHCHCH2 ________________________________________
Br CH3 Br
- H – C – C – C = C – C – H
H CH3 H
- The diagram below shows some reactions involving hydrocarbons.
- Identify the following (5 Mks)
I – substance L
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II – Substance M
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III – Substance Q
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IV – Process P
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V – Process N
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- Name two substances that can be used as catalysts during process W. (2 Mks)
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- Nitrogen (iv) oxide is one of the oxides of nitrogen.
- Name the other two oxides of nitrogen (2 Mks)
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- Which of the oxides you have named in a(i) above relights a glowing splint. (1 Mk)
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- Ammonia is a compound of nitrogen that can be obtained industrially by the Haber process;
- Other than nitrogen, name the other raw material for this process. (1 Mk)
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- Write a chemical equation of the reaction that occurs in the catalytic chamber to produce Ammonia. (1 Mk)
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- State one use of ammonia (1 Mk)
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- When burning magnesium is lowered into a gas jar containing air magnesium oxide is one of the products formed. Name the other product that can possibly be formed. (1 mk)
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