WASSCE CHEMISTRY MAY/JUNE 2015 (SSCE WAEC MAY/JUNE 2015 CHEMISTRY)
1.The negatively charged particle in an atom is the
2. How many orbits are contained in an atom with atomic number 13?
3. The Van der waals' forces are dominant intermolecular forces in_______?
A. Ammonium chloride
C. Sodium chloride
4. The compound formed between 14X and 16Y is _______?
5. The shape of a molecule of water is _______?
6. A metallic ion Z2+ with an inert gas structure contains 18 electrons. How many protons are contained in this ion?
7. Which of the following pairs of compounds belongs to the same homologous series?
A. C3H8 and C3H6
B. C4H10 and C5H10
C. C2H4 and C4H10
D. C2H6 and C4H10
8. Which of the following pairs of elements forms amphoteric oxides?
A. Be and Mg
B. Na and K
C. B and Al
D. Si and Pb
9. The following transition metal ions would be coloured in aqueous solution except________?
10. The gas given off when ethanol reacts with sodium is
11. Which of the following halogens is solid at room temperature?
12. The alkaline earth metals have similar chemical properties because________?
A. They are in the same period
B. Their salts are colourless
C. They have the same number of valence electrons
D. They are very reactive
13. The number of unpaired electrons in an atom of an element 8Q is _______?
14. The bond formed when ammonia reacts with hydrogen ion to form ammonium ion is
C. Hydrogen bond
15. To which group and period respectively does an element with 15 electrons belong?
A. 3 and 3
B. 3 and 5
C. 5 and 3
D. 5 and 5
16. The shape of a graphite crystal is
17. Which of the following oxides is ionic?
18. Which of the following substances when boiled with aqueous solution of sodium hydroxide would be hydrolyzed?
C. i and ii
D. ii and iii
19. Which of the following trioxonitrate(V) salts would decompose on heating to form a metal?
20. Consider the following reaction equation:
C2H4(g) + 3O2(g) → 2CO2(g) + 2H2O(g)
The volume of CO2(g) produced at s.t.p when 0.05 moles of C2H4(g) was burnt in O2(g) is
[Molar Volume of gas = 22.4dm3]
21. The number of oxygen molecules present in 16.0g of the gas is ______?
[Avogadro's number = 6.02 × 1023]
A. 6.02 × 1022
B. 6.02 × 1023
C. 3.01 × 1023
D. 1.51 × 1023
22. Consider the following reaction equation:
SO42-(aq) + 2H+(aq) + ye- →SO42-(aq) + H2O(1)
The value of y in the equation is
23. The general gas equation was derived from______?
A. Boyle's and Gay Lussac's laws
B. Boyle's and Graham's laws
C. Boyle's and Charles' laws
D. Dalton's atomic theory
24. The vapour pressure of a liquid depends on:
II. rate of condensation
III. Cohesive forces holding the particles together.
B. I and II
C. I and III
D. II and III
25. Which of the following gases will diffuse most rapidly?
[H = 1.00, C = 12.0, O = 16.0, S = 32.0, Cl = 35.5]
26. When a reaction is endothermic
A. Enthalpy change, ΔΔH is negative
B. Heat content of a product is less than the heat content of a reactant
C. Heat content of reactants is less than the heat content of product
D. The reaction is non-spontaneous
27. Which of the following statements about intermolecular distances and cohesive forces between gas is correct? They are
A. Both large
B. Both negligible
C. Constant and negligible
D. Large and negligible
The following diagram illustrates the rate curve that was obtained when Mg reacted with excess dilute HCl.
The diagram became horizontal at X because
A. The reaction was slowed down
B. All the dilute HCl has reacted
C. All the Mg has reacted
D. Hydrogen gas is produced at a steady rate
29. An example of an acid salt is
30. Which of the following oxides can be reduced by hydrogen?
A. Aluminium oxide
B. Magnesium oxide
C. Sodium oxide
D. Silver oxide
31. Solubility is practically applied in
A. Fractional distillation
B. The determination of pH
C. The determination of saturation in hydrocarbons
D. Solvent extraction
32. Which of the following compounds is the least soluble in water?
33. A substance which dissolves readily in organic solvent would
A. Be a covalent compound
B. Have strong electrostatic forces of attraction
C. have a high melting point
D. Conduct electricity in molten state
34. Consider the following equilibrium system:
2SO2(g) + O2(g) ⇌2SO3(g)
The addition of more O2(g) to the system will shift the equilibrium position to the
A. Right leading to the production of more SO3(g)
B. Right leading to the production of more SO2(g)
C. Left leading to the production of more SO2(g)
D. Left leading to the production of more SO3(g)
35. A change in the temperature of a saturated solution disturbs the equilibrium between the
A. Undissolved solute and the solvent
B. Dissolved solute and the solvent
C. Dissolved solute and the undissolved solute
D. Dissolved solute and the solution
36. Which of the following statements about an electrochemical cell is correct? Oxidation occurs
A. At the anode
B. At the cathode
C. Through the salt bridge
D. In the aqueous solution
37. Consider the following reaction equation:
CuO(s) + H2(g) $\rightleftharpoons$ Cu(s) + H2O(1)
Which substance is oxidized?
38. Which of the following metals is the strongest reducing agent?
39. The complete hydrogenation of benzene gives
40. A compound has an empirical formular CH2O and molecular mass of 90.
[H = 1.00, C = 12.0, O = 16.0]
41. Which of the following reactions would take place when concentrated sodium hydroxide solution is added to palm oil?
42. Starch could be converted to glucose by the process of
43. Which of the following compounds is a secondary alkanol?
44. Which of the following substances is a heavy chemical?
B. Barium Hydroxide
C. Hydrochloric acid
45. Which of the following process does not take place in domestic water treatment?
46. A substance responsible for the sour taste of unripe orange is
C. Alkanoic acid
47. Which of the following products of biotechnology can be used as a fuel in place of petrol?
48. Which of the following polymers in thermosetting?
49. The correct balanced equation for the reaction between aluminum metal and hot concentrated tetraoxosulphate(VI)acid is ?
A. 2AI(s) + 6H2SO4(1) → AI2(SO4)3(aq) + 6H2O(1) + 3SO2(g)
B. 2AI(s) + 3H2SO4(1) → AI2(SO4)3(aq) + 6H2O(1) + 3SO2(g)
C. 2AI(s) + 4H2SO4(1) → AI2(SO4)3(aq) + 8H2O(1) + 3SO2(g)
D. 2AI(s) + 5H2SO4(1) → AI2(SO4)3(aq) + 8H2O(1) + 3SO2(g)
50. Which of the following gases is monoatomic?