Chemistry Questions and Answers for Secondary School Students
Instructions: Answer all questions
1. Reaction represented by the equation C_6 H_12 O_6 □(→┴Zymase 2C_2 H_S OH+2CO_2 ) is known as A. Hydrolysis B. Oxidation C. Reduction D. Fermentation
2. The reaction represented by the equation NaOH(aq)+ HCL(aq)→NaCl+H_2 O A. is a double decomposition reaction B. Is a neutralization reaction C. Is reversible D. Is usually catalyzed.
3. Which of the following does NOT affect the rate of a chemical reaction? A. Concentration of the reactants B. Addition or presence of a catalyst C. size of the reacting particles D. The enthalpy change for the reaction.
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4. Given that 32.0g of sulphur contains 6.02 x 1023 sulphur atoms, how many atoms are there in 2.70g of aluminum? A. 6.02 x 1023 B. 3.01 x 1023 C. 6.02 x 1022 D. 5.08 x 1022
5. A salt which has loses mass when exposed to air is A. Hygroscopic B. Deliquescent C. Efflorescent D. Fluorescent.
6. The following are heavy chemicals EXCEPT A. tetraoxosulphate(vi) acid B. Caustic Soda C. Sodium trioxocarbonate(iv) D. Dyes.
7. Which of the following correctly explains why iodine crystals change directly into the gaseous state when heated? A. Iodine crystals sublime B. Iodine atoms are held together by strong forces C. Iodine molecules are held together by strong forces D. Iodine molecules are covalent.
8. The major raw material in the plastic industry is A. Ethanol B. Sulphur C. Methylethanoate D. Ethene
9. When an element can exist in two or more forms in the same physical state, the element is said to exhibit A. Isotopy B. Isomerism C. Allotropy D. Hygroscopy
10. What is the concentration, in moldm-2, of a solution containing 0.10g of sodium hydroxide per 50cm3 of solution? A. 0.05 B. 0.1 C. 0.5 D.2
11. The following are s-block elements EXCEPT A. Lithium B. Magnesium C. Aluminum D. Barium The electronic configurations of two atoms X and Y are as follows;
X: 1S2 2S2 2P6 351, Y; 1S22S2 2P6 3S2 3P6 4S2.
12. Which of the statements below is true of the position of X and Y in the periodic table?
A. X belongs to group 1, Y belongs to period 2
B. X belongs to group 1, Y belongs to period 4.
C. X belongs to group 2, Y belongs to period 1
D. X belongs to group 3, Y belongs to period 2
13. The oxidation number of chloride is +1 in A. KClO3 B.Cl2O7 C. ZnCl2 D. NaClO
14. Which of the following separation is routinely applied in the petroleum industry A. Filtration B. Chromatogrphy C. Evaporation D. Fractional distillation
15. What does X stand for in the following expression? X = -log10 [H+]
A. Enthalpy change, ∆H B. Equilibrium constant, K C. Solubility product D. Degree of acidity, pH
16. Which of the following indicates correctly the increasing order of oxidizing power of the halogens? A. F<Cl<Br C. I<Cl<Br<F
17. Which of the following compounds has the highest ionic character?
A. KCl(s) B. BeCl2(s) C. HCl(g) D. AlCl3(s)
18. What is the percentage by mass of copper in copper (i) oxide A. 88.9% B. 80.0% C. 66.7% D. 20.0%
19. A weak acid is one which A. Is not corrosive B. Is slightly ionized in water C. Does not produce salts with alkalis D. Does not conduct an electric current in aqueous solution
20. Alums are classified as A. Simple salts B. Acid salts C. Anhydrous salts D. Basic salts
Which of the following oxides is amphoteric? A. Na2O B. Fe2O3 C. Al2O3 D. CaO
21. When an atom gains an electron, it becomes A. Chemically inactive
B. Negatively charged C. Oxidized D. A cation
22. The rate of production of hydrogen gas from the reaction between zinc granules and hydrochloric acid can be increased by A. Cooling the reaction mixture B. Using zinc powder instead of zinc granules C. Using Zinc rod instead of Zinc granules D. carrying out the reaction at a higher pressure.
23. What is the role of MnO¬2 in the reaction represented by the following equation? MnO2 + 4Hcl→ A. Bleaching agent B. Reducing agent C. Catalyst D. Oxidizing agent
24. The following are properties of transition metals EXCEPT A. Variable oxidation states B. tendency to form complex ions C. low melting points D. Ability to act as catalyst.
25. The major air pollutants that can result from smoky vehicles include I. Acid fumes II. Hydrogen sulphide III. Carbon (ii) oxide IV. Carbon particles A. I, II, III, IV B. I, II only C. I and IV only D. II, III, IV only
26. The phenomenon observed when dust particles collide randomly in a beam of sunlight is known as A. Tyndal effect B. Diffusion C. Osmosis D. Brownian movement.
27. A given volume of methane diffuses in 20 seconds. How long will it take the same volume of sulphur (iv) oxide to diffuse under the same conditions? A. 5 seconds B. 20 seconds C. 40 seconds D. 60 seconds
28. These are factors affecting the rate of chemical reactions EXCEPT
A. Surface area B. Catalyst C. Nature of reactants D. Equilibrium position
29. Factors which can contribute to environmental pollution include I. Overpopulation II. Chemical warfare III. Agricultural activities IV. Industrialization A. I, II only B. II, III only C. III, IV only D. I, II, III IV
30. Which of the following contains the highest number of electrons in the outermost shell? A. O B. Ne C. P D. K
31.Pauli’s exclusion principle is related to A. Quantum numbers of electrons B. Reversibility of equilibrium reactions C. Electronegative values of elements D. Collision theory of reaction rates
32. Which of the following properties increases dawn a group in the periodic table? A. Atomic radius B. Electronegativity C. Electron affinity D. Limization energy
33. In the periodic table, elements that lose electrons most readily belong to A. Group 1A B. Group IIA C. Group IIIA D. Group IIIA
34. The type of chemical bond that exist between potassium and oxygen in potassium oxide is A. Ionic B. Metallic C. Covalent D. Dative
35. What is the value of x in the following equation?
Cr2 O_7^(2-)+ 14H^++ Xe^-→2Cr^(3+)+7H_2 O A.1 B.6 C.8 D.12
36. Which of the following procedures is suitable for identifying the food colourng added to a pastry sample? A. carry out some food tests B. Examine the pastry sample under a microsocope C. Do a chromatogram of the colouring extract D. Determine the molar mass of the colouring
37. Which of the following statement about idea gases is/are correct? I. The cohesive forces between their particles are negligible. II. They have no definite volume, but occupy the volume of their containers III. They are not compressible IV.
Their particles collide with loss of energy A. I only B. I and II only C. I, II and III only D. I, II, III, IV
38. What is the oxidation number of nitrogen in Al (NO3)3? A. +1 B. +3
C. +5 D. +6
39. What is oxidized in the reaction represented by the following equation? 3Cu+8HNO3 3Cu(NO3)2 + 2NO + 4H2O A. Oxygen B. Hydrogen C. Nitrogen D. Copper
40. Which of the following establishments uses the process of fermentation in its operation? A. Fertilizer B. Textile industry C. Brewery D. Soap manufacturing industry.
41. The relative molecular mass of an element is NOT a whole number; it can be deduced tat the element is A. naturally radioactive B. Abundant in nature C. A transition metal D. An isotopic mixture
42. Calculate the mass of sodium hydroxide in 5.00dm3 of a 0.125mol dm-3 Solution A. 0.0156g B. 0.625g C. 1.00g D. 25.0g.
43. One of the methods used for combating air pollution is A. Burning of solid waste B. Provision of sanitary land fills C. Legislation against some industrial practices D. Scavenging of refuse dumps
44. Which of the electrons in the following orbital will experience the gratest nuclear attraction? A. 1s electron of helium B. 1s electron of potassium C. 2s electron of boron D. 2s electron of carbon.
45. An element Q forms a compound QCls. In which group of periodic table is Q? A. I B. II C. V D. VII
46. Which of the following arrangements is in order of increasing ionization energy? A. AI, Si, P.S B. Si, Al,s P C. S, P, Si, Al D. P, Si, S, Al
47. What is the percentage by weight of calcium in CaCoCl2? A. 28.0%
B. 31.6% C. 43.8% D. 44.5%
48. A catalyst increases the rate of chemical reaction by A. Decreasing the temperature of the reaction B. Decreasing the activation energy of the reaction C. Increasing the surface area of the reactants D. Decreasing the surface area o the products.
49. Which of the following oxides of Nitrogen has oxidation number of +1 A. KNO3 B. N2O C. N2O2 D. NO
SECTION B – THEORY [80MARKS]
Instruction: This section consist of the parts, answer atleast one (1) question from each part and four (4) questions in all
1. The following table gives the atomic numbers of element V, W, X, Y and Z
Element V W X Y Z
Atomic number 11 16 18 19 24
(a) Which of the elements
(i) belong(s) to group 1? (ii) is/are noble gas(es)? (iii) form(s) ionic compounds(s)?
(iv) form(s) an anion? (v) react(s) with water to liberate hydrogen?
(vi) React(s) with water to form alkaline solution?
b(i) What is meant by “first ionization solution?
(ii) List three properties of electrovalent compounds
(iii) Consider the following pairs of element (I) 9F and 17Cl;
(iv) 12Mg and 2-Ca. explain briefly why the elements in each pair have similar chemical properties.
2a(i) What is the common name given to the group VII elements?
(ii) Name the hydrides of the first two elements in group VII
(iii) State THREE chemical properties of group VII elements
b. Copy and complete the following table
Particles Number of neutron Number of electrons Number of protons Mass number
W2+ 12 24
X2- 8 16
Y 13 27
Z 12 11
c. Define each of the following (i) Ion (ii) Isotopes (iii) periodic law
d. Define each of the following and state their variations in the period table
(i) atomic radius (ii) electron affinity (iii) electronegativity
3a. Write short notes on the following reaction giving examples in
Reversible reaction (ii) Double Decomposition reaction
(iii) Thermal dissociation reaction
b. Define accurately the term catalyst and give FIVE characteristics of a catalyst
c. Differentiate between homogenous and heterogeneous catalysis
d. Show that the following reactions are oxidation – reducing reactions, indicating with reasons the oxidizing and reducing agents
i) 2H2S(g) + SO2(g) → 2H2O(l) + 3S(s) (ii) 2FeCl2(g) + Cl2(g) → 2FeCl3(aq)
4a. Define the following, giving an example of a compound in each case
(i) Oxidizing agent (ii) Reducing agent
b. When hydrogen sulphide is burnt in oxygen to form sulphur(iv) oxide and water;
i. Write a balanced equation for the combustion
ii. How does the oxidation number of sulphur change?
c. Balance the following Redox reaction in acidic medium using the half – reaction method
MnO4 + SO2 → Mn2+ + SO_4^(2-)
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