Chemistry Exam Questions| First Term Examination, 2020/2021 Session
CLASS: SS 3 SUBJECT: Chemistry TIME: 2 HOURS
Chemistry Examination questions for secondary school students to aid in effective learning process.
These Chemistry questions and answers have been properly prepared to assist every students in their preparation for any upcoming examination; Primarily Compiled and assembled to serve as a reference material to help teachers draw up test and exam questions faster.
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SECTION A – OBJECTIVES [50MARKS]
Instructions: Answer all questions
1. The atoms of four elements are represented as 20Q, 16R, 10S and 8T. which of the elements would be unreactive A. Q B. R C. S D. T
2. The type of chemical bond that exists between potassium and oxygen in potassium oxide is A. Ionic B. Metallic C. Covalent D. Dative
3.Chlorine atom forms Cl- by A. Losing one electron B. Sharing one electron C. Donating one pair of electrons D. Gaining one electron
4. An element Z has a combining power of 3. Which of the following formulae is correct of its compound A. ZSO3 B. Z3Cl2 C. Z2O3 D. ZS3
5. The gas evolved when dilute tetraoxosulphate(iv) acid reacts with sodium hydrogentrioxocarbonate(iv) is A. Hydrogen B. Oxygen C. Carbon(iv)oxide D. Sulphur(vi)oxide
6. If a solution has a pH of 2, it can be concluded that it A. Is a weak electrolyte B. has hydrogen concentration of 0.2moldm-3 C. Is twice as acidic as a solution of pH, D. Will produce effervescence with magnesium ribbon.
7. Chemical equilibrium is attained when A. Reactants in the system are used up B. Concentrations of the products are greater than those of the reactants C. Concentrations of the reactants and products remain constant D. reactants stop forming the products
8. An iron nail placed in a solution of copper(ii)tetraoxosulphate(vi) is soon covered with a deposit of copper. Which of the following equations represents the reaction?
A. Fe2+(aq) + Cu(s) Fe3+(aq)
B. Fe2+(aq) + Cu(s) Fe(s) + Cu2+(aq)
C. Fe(s) + Cu2+(aq) Fe2+(aq) + Cu2+(aq)
D. Fe(s) + Cu2+(aq) Fe2+(aq)
9. Which of the following non-metals reacts most readily with metals? A. Nitrogen B. Chlorine C. Sulphur D. Carbon
10. A radioactive substance is best stored A. Under paraffin oil B. Under ultravidet light C. In a cool, dark cupboard D. In a box lined with lead
11. In the electrolytic extraction of aluminum from puried alumina; molten cryolite is added in order to A. lower the melting point of the alumina B. Prevent the aerial oxidation of the molten aluminum C. Lower the activation energy of the reaction D. Form a protective crust on top of the electrolyte
12. When iron rusts, it undergoes A. Deliquescence B. Chemical decomposition C. Hydrolysis D. Redox reaction
13. Which of the following involves the decomposition of a sugar by enzymic action? A. Esterification B. Fermentation C. Dehydration D. Polymerization
14. If a reaction is said to be exothermic, which of the following statements is a correct deduction from the information? A. The reaction vessel gets hotter as the reaction proceeds B. ∆H for the reaction is positive C. The rate of the reaction increases with time D. The activation energy of the reaction is high
15. A dye s suspected to have contaminated a lollipop. Which of the following is the best method by which the contaminant may be isolated?A. Fractional distillation B. Recrystallization C. Filtration D. Paper Chromatography
16. Which of the following accounts for the difference in the mode of conduction of electricity by metals and aqueous salt solutions?
A. Electrons are present in metals but not in salt solutions B. Metals are conducted while salts are electrolytes C. Electricity is carried by mobile electrons in metals but by ions in aqueous salt solution D. Salts ionize in aqueous solutions while metals do not.
17. A positive brown ring test indicates the presence of A. NO-3¬ B. Fe3+
C. 〖SO〗_3^(2-) D. Cu+
18. The following statements about graphite are correct EXCEPT that it A. Is used as a lubricant B. Has a network structure C. Contains mobile free electrons D. Is a good conductor
19. Which of the following hydrocarbons is unsaturated? A. Ethane
B. Benzene C. Propane D. Z-methylbutane
20. Which of the following is an alloy of mercury? A. Stainless steel B. Soft solder C. Coinage bronze D. Amalgam
21. Metals which react with steam only when they are red-hot include
A. Copper B. Sodium C. Calcium D. Iron
22. An arrangement of two different metals in aqueous solutions of their salts to produce an electric current is known as A. Electrochemical cell B. Activity series C. Thermocouple D. Volmeter
23. Which of the following exhibits resonance? A. Benzene B. Butane
C. Pentene D. Octane
24. Which of the following metals will be the most suitable for use where lightness and resistance to corrosion are of important? A. Lead B. Copper C. Iron D. Aluminum
25. What is the most probable group of an element which is a soft, silvery-white solid and reacts violently with water? A. Group O B. Group 1 C. Group 4 D. Group 6
26. Which of the following ions will migrate to the cathode during electrolysis? A. Zinc ions B. Chloride ions C. Suphide ions D. Tetraoxosulphate(vi)ions
27. Which of the following radioactive decays involve an ∝-β emission?
A. (_92^238)U →(_90^234)Th +(_2^4)He B. (_80^238)Hg →(_81^238)Tl C. (_50^199)Sn →(_50^199)Sn
D. (_1^2)H+ (_1^2)H →(_1^3)H + (_1^1)H
28. The following oxides react with both acids and bases to form salts except A. Zinc oxide B. Lead (ii) oxide C. Aluminium oxide D. Carbon(iv)oxide
29. Which of the following metals is NOT extracted by electrolysis? A. Iron B. Sodium C. Calcium D. Magnesium
30. Which of the following is an ore of aluminum? A. Haematite B. Magnetite C. Siderite D. Bauxite
31. Which of the following statements is/are correct about metals? They I. Are good conductors of electricity II. Have mobile electrons III are reducing agent IV. Form acidic oxides A. I and II only B. I, II and III only C. I, II, III and IV D. None of the above.
32. The main type of reaction that occurs in the blast furnace during the extraction of Iron is A. reduction reaction B. Decomposition C. Exothermic reaction D. Combustion
33. Which of the following compounds can be represented by the molecule formula C2H6O A. Propanal B. Ethanol C. Methanoic acid D. Glucose
34. The following compounds are hydrocarbons EXCEPT A. Methylpropanoate B. Z-methylbutane C. Benzene D. Cyclohexane
35. When alkynes are hydrogenated completely, they produce compounds with the general molecular formula A. CnHn B. CnH2n+2 C. CnH2n D. CnH2n-2
36. Which of the following alloys does not contain copper? I. Brass II. Bronze III. Steel A. I only B. II only C. III only D. II and III only
37. The major product in the solvay process is A. NaOH B. Na2CO3 C. NH3 D. H2SO4
100g of radioactive mass has a half-life of 5 days. Calculate the mass decayed off after 15 days. A. 25g B. 50g C. 12.5g D. 6.25g
38. A solution of sodium trioxocarbonate(iv) contains 10.6g in 250cm3 of solution. Calculate the concentration of the solution. A. 0.4moldm-3 B. 1.0moldm-3 C. 10.6moldm-3 D. 25.0moldm-3
39. The rate of chemical reaction of solids are not affected by A. Catalyst B. pressure C. Particle size D. Temperature
40. The energy change that accompanies the addition of an electron to an isolated gaseous atom is A. Bond energy B. electronegativity C. electron affinity D. Ionization energy
Which of the following metals could be used as sacrificial anode for preventing the corrosion of iron? A. Copper B. Lead C. Magnesium D. Silver
41. What mass of copper would be formed when a current of 10.0A is passed through a solution of CuSO4 for 1hour? A. 5.9g B.11.8g C. 23.7g D. 47.3g¬
42. The volume occupied by 0.4¬¬g of hydrogen gas at S.t.p is A.2.2dm3
B. 4.48dm3 C. 22.4dm3 D. 44.8dm3
43. The oxidation number of Fe in [Fe(CN)6]3- is A. +3 B. +2 C. -2 D. -3
Which of the following substances is mainly responsible for the depletion of the ozone layer? A. Oxygen B. Chlorofluorocarbon C. Carbon(ii)oxide D. Nitrogen(ii)oxide
44. Which of the following reactions is common to all hydrocarbons?
A. Combustion B. Addition C. Polymerization D. Condensation
45. A hydrocarbon compound contains 92.3% carbon. Determine its empirical formula A. CH B. CH2 C. CH3 D. C2H3
46. Reduction is the process of A. Loss of electron B. Loss of hydrogen C. loss of oxygen D. Addition of electronegative elements
SECTION B – THEORY
Instruction: This section is divided into two parts, answer only two questions from each part.
PART I [ 50 MARKS]
1.(a) What are nucleons?
(b) State Graham’s law of diffusion
(c) Explain briefly why aluminum does not corrode easily
(d) State THREE examples of periodic properties and their variations in the periodic table of elements
(e) State TWO reasons why real gases deviate from ideal gas behave iour
(f) List THREE uses of fractional distillation in industry
(g) What factors determine the selective discharge of ions at the electrodes during electrolysis?
(h) Consider the reaction represented by the following equation
Na2CO3(aq) + MgCl2 2NaCl(aq) + MgCO3(aq)¬
2a. Consider the following atoms
(_T^(R ))X; (_T^S) X
i. State the phenomenon exhibited by the two atoms
ii. What is the difference between the atoms?
iii. Give two examples of elements that exhibit the phenomenon stated in 2(a)(i)
iv If T is 17, write the electron configuration of the element
b(i) State two differences between metals and non-metals with respect to their: I. Physical properties (ii) Chemical properties
b (ii) Give one example of each of the following compounds
An amphoteric oxide
A hydride which evolves hydrogen when reacted with water;
A trioxocarbonate(iv) salt which is readily decomposed on heating
A chloride salt which is readily hydrolyzed in water
c(i) State THREE characteristic properties of transition metals
(ii) Write the electro configuration of 30Zn
(iii) Explain briefly why zinc is not considered as a typical transition element
3(ai) State Graham’s Law of diffusion
(aii) If 100cm3 of oxygen diffused in 4seconds and 50cm3 of gas Y diffused in 3 seconds, Calculate the relative molecular mass of gas Y
X(g)+2Y(g XY2(g)¬ ∆H = -52KJmol-1
i) State what happens to the yield of XY2 when the temperature is increased
(ii) Explain the effect of decrease in pressure on the equilibrium position
(iii) State the effect of a catalyst on the
Position of equilibrium
c.(i) State two differences between the solubilities of solids and gases in liquids
c.(ii) Name the physical properties used in choosing separation techniques for the following mixtures I. Kerosene and Petrol II. Calcium trioxocarbonate (iv) and potassium chloride III. Ammonium chloride and sodium chloride
d(i) State a method of preparing each of the following salts;
Lead (II) Trioxocarbonate (iv)
Iron (ii) Chloride
Copy and complete the table below
D(i) State the difference between analydrous and hydrated salts
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