# WASSCE CHEMISTRY MAY/JUNE 2012 (SSCE WAEC MAY/JUNE 2012 CHEMISTRY)

1. The number of orbitals in a p – sub level of an atoms is

A. 2

B. 3

C. 5

D. 6

2. Which of the following electron configurations represents that of a atom in its ground state

A. $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{1}}3{{p}^{1}}$

B.  $1{{s}^{2}}2{{s}^{1}}2{{p}^{1}}$

C. $1{{s}^{2}}2{{s}^{1}}2{{p}^{3}}$

D.$1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{0}}$

3. A beam of particles was passed between charged plates as illustrated in the diagram below

A. Electron, neutron and proton

B. electrons, proton and neutron

C. Proton, neutron and electron

4. Which of the following ions has an electron configuration different from the others?

A. $_{17}C{{l}^{-}}$

B. $_{8}{{O}^{2-}}$

C. $_{12}M{{g}^{2+}}$

D. $_{13}A{{l}^{3+}}$

5. The atomic radii of metal are usually

A. greater than their ionic radii

B.  equal to their ionic radii

C. less than their ionic radii

D. less than those of non-metal in the same period

6.Two elements, X and Y are in the same group on the periodic table because they both have the same

A. umber of electronic shells

B. number of valence electrons

C. atomic size

D. atomic number

7. The d – block elements are paramagnetic because they

A. contain paired electros which are repelled by magnetic field force

B. contains unpaired electrons in the partially filled 3d – orbital.

C. form coloured complex ions that attract magnetic lines of forces

D. have delocalized valence electrons

8. Which of the following statement about a radioactive substance is/are correct?

I it emits radiation continuously and spontaneously

II. The emitted radiation are affected by temperature and pressure

III. The radiation ca penetrate opaque matter

A. II only

B.  I and II only

C. I and III only

D. II and III only

9. Which of the following elements is a metalloid?

A. Carbon

B. Oxygen

C. Silicon

D. Sodium

10. Which of the following halogens is liquid at room temperature?

A. Chlorine

B. Fluorine

C. Iodine

D. Bromine

11. The shape of graphite crystal is

A. tetrahedral

B. pyramidal

C. hexagonal

D. Octahedral

12. The compound formed by the combination of two elements with a large electronegativity difference is likely to be

A. polar covalent

B. giant molecular

C. covalent

D. ionic

13. The complex compound formed whe aluminium dissolves in aqueous sodium hydroxides is

A. Na3Al(OH)4

B. NaAl(OH)4

C.NaAl(OH)3

D. Na2Al(OH)3

14. The vapour pressure of a liquid depends on

I. temperature

II. rate of condensation

III. cohesive forces holding the particles together

A. I only

B. I and II only

C. I and III only

D. II and III only

15. MgO does not readily dissolve in water because

A. of its high melting point

B. it is a covalent compound

C. it form a hydroxide whe dissolved in water

D. its lattice energy is higher than its hydration energy

16. Consider the following reaction equation;

$CaC{{O}_{3(s)}}+2HC{{l}_{(aq)}}\to CaC{{l}_{2(aq)}}+{{H}_{2}}{{O}_{(l)}}+C{{O}_{2(g)}}$

What mass of CaCl2 would be obtained when 25.0g of CaCO3 is reacted with excess HCl(aq)?

[CaCO3 =100; CaCl2 =111]

A. 4.00g

B.4.44g

C. 18.9g

D. 27.8g

17. The number of sulphur atoms in 3.20g of SO2 is

[O =16.0; S = 32.0; Avogadro =6.02 × 1023]

A. 3.01×1022

B. 6.02×1022

C. 6.02×1023

D. 1.20×1024

18.Consider the reaction represented by the following equation:

$xC{{H}_{3}}OH+y{{O}_{2}}\to 2C{{O}_{2}}+z{{H}_{2}}O$

The values of x, y, and z respectively are

A. 2, 3 and 4

B. 2, 4 and 3

C. 1, 2 and 3

D. 1, 3 and 5

19.The formula of mercury(I) dioxonitrate (III) is

A. HgNO3

B. Hg2NO2

C.  Hg(NO2)2

D. Hg(NO3)2

20. A sample of a gas may be identified as chlorine if it turns

A. damp blue litmus paper red

B. lime water milky

D. starch iodide paper blue-black

21. A metal M forms two types of chlorine MCl and MCl3. Which of the following law best explains the relationships the chlorides. Law of

A Conservation of mass

B. definite proportion

C. multiple proportion

D. reciprocal proportion

22. Which of the following metals would readily displace hydrogen from steam?

A. copper

C. magnesium

D. silver

23. The volume of occupied by 0.4g of hydrogen at s.t.p is

[H= 1.00; Molar volume at s.t.p =22.4dm3]

A. 2.24dm3

B. 4.44dm3

C. 22.4dm3

D. 44.8dm3

24. When a substance changes directly from gaseous state to solid state without forming a liquid, the substance is said to

A. condense

B. evaporate

C. sublime

D. precipitate

25.At ordinary temperature H2O is a liquid while H­2S is a gas. This is because H2O has

A. weak intermolecular forces holding it molecules together

B. Strong hydrogen bonds holding its molecules together

C. induced dipole-induced dipoles forces between its molecules together

D. ionic forces between its molecules

26. The postulate that molecules are in a constant random motion best explains why liquids

A. can undergo solidification

B. maintain their volumes

C. are incompressible

D. have no characteristic shape

27. Which of the following gases has the lowest rate of diffusion under the same condition?

[H=1.00, He = 4.00, O =16; Cl =35.5]

A. Cl2

B. H2

C. He

D. O2

28. The energy evolved when magnesium burns in air is in the form

A. heat

B. heat and sound

C. light and heat

D. Sound

29.The substance L reacts with NH4NO3(aq) to generate ammonia gas. L is likely to be

A. HCl

B.NaOH

C. CH3COOH

D. CaSO4

30. On heating the following trioxocarbonate (IV) salts decompose to give solid residue except

31. Which of the following pH values indicate that a solution is a strong base?

A. 1

B. 5

C> 9

D. 13

32. The hydrolysis of NH4Cl gives a

A. am acidic solution

B. an alkaline solution

C. a buffer solution

D. a neutral solution

33. A spot of oil paint of a shirt can best be removed using

A. brine

B detergent

C. Kerosene

D. Warm water

Consider the following solubility curves

34. Which of the following deduction could be correctly made from the graph ?

A. The  solubility of U is not affected by change in temperature

B. The solubility of S decreases with increasing temperature

C.C. T is most soluble among the salts

D. S is the least soluble among the salts

35. Consider the reaction represented by the following equation

$Cu{{O}_{(g)}}+{{H}_{2}}S{{O}_{4(aq)}}\to CuS{{O}_{4(aq)}}+{{H}_{2}}{{O}_{(l)}}$

Which of the following factors will not affect the rate of the reaction?

A. Particles size of CuO(s)

B. Concentration of H2SO4(aq)

C. The temperature of the reacting mixture

D. Pressure of reaction system

Use the following graph to answer question 36 and 37

The activation of the reaction is

A. 40KJ

B. 60KJ

C. 80KJ

D.  120KJ

37. The type of reaction represented by the graph is

A. endothermic

B. exothermic

C. catalytic

D. Spontaneous

38.,. Which of the following devices function on redox reaction?

I Dry cell

II. Car battery

III. Electric generator

A. I and III only

B. II and III only

C. I and II only

D. I , II and III

39. The oxidation number of Fe in [Fe(CN)6]3 iis

A +3

B. +2

C. –2

D.–3

40. Consider the following reaction equation

${{C}_{16}}{{H}_{34}}\to {{C}_{5}}{{H}_{12}}+{{C}_{11}}{{H}_{22}}$

The process represented by the equation is

A. Cracking

B. fermentation

C. Polymerization

D. reforming

41. Consider the following structures of organic compounds

Which of the following statements about the structure is not correct? They

A.  are geometric isomers

B.  are saturated hydrocarbons

C. have similar physical properties

C. are members of the same homologous series

42. Which of the following substances would not produce ethanol when fermented ?

A.Cane sugar

B. Glucose

C. Starch

D. Vinegar

43. An alkanol can be prepared by the reaction of an alkene with

A. concentrated tetraoxosulphate (VI) acid

B. bromine in tetrachloroethane

C.  aqueous potassium tetraoxomanganate (VII)

D. sodium hydroxide solution

44. A compound contain 7.75% hydrogen, 37.21% carbon and 55.04% chlorine . Determine the empirical formula of the compound  [H=1.00, C= 12.0, Cl=35.5]

A.C2H3Cl

B. C2H5Cl

C. C3H8Cl

D. C5H2Cl

45. A tertiary alkanol has a molecular formula C4H10O. What is the structural formula of the compound?

A.${{(C{{H}_{3}})}_{2}}CHC{{H}_{2}}OH$

B.$C{{H}_{3}}C{{H}_{2}}CH(OH)C{{H}_{3}}$

C. ${{(C{{H}_{3}})}_{3}}COH$

D.$C{{H}_{3}}C{{H}_{2}}C{{H}_{3}}C{{H}_{2}}OH$

46. Which of the following industrial process depends on the actions of enzymes

A. liquefaction of air

B. manufacture of soap

C. Brewing of beer

D. Catalytic cracking

47.Which of the following pollutants is not usually recycled

A. Aluminium cans

B. Glass bottles

C. Nuclear wastes

D. paper wastes

48. A metal that is widely used in the manufacture of paints and overhead electric cables is

A. aluminium

B. copper

C. iron

49. Brass is a mixture of

A. Cu and Sn

B. Cu and Zn

C. Cu and Mg

D. Cu and Pb

50. Which of the following substance is mainluy responsible for the depletion of the ozone layer?

A. Oxygen

B. Chloroflurocarbon

C. Carbon(II) oxide

D. Nitrogen (II) oxide

WAEC SUBJECTS:
Year of WASSCE EXAM: