WAEC - Chemistry (2013)

  • 1
    Which of the following instruments is used in detecting the presence of radiation?
    Odpowiedź
    (B)
    Geiger-Muller counter
  • 2
    The molecule which has a linear shape is
    Odpowiedź
    (D)
    CO2
  • 3
    The formula of the compound formed between a trivalent metal, M and a divalent non-metal, Y is
    Odpowiedź
    (A)
    M2Y3
  • 4
    An atom of an element X gains two electrons. The symbol of the ion formed is
    Odpowiedź
    (C)
    X 2-
  • 5
    Which of the following statements is correct?
    Odpowiedź
    (D)
    Cations are smaller than the parent atom
  • 6
    Which of the following arrangements represents the correct order of electronic energy level?
    Odpowiedź
    (C)
    1s 2s 2p 3s 3p 4s 3d
  • 7
    The element with electron configuration 1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^1\) belongs to
    Odpowiedź
    (D)
    p-block, period 3, group 3
  • 8
    In the periodic table all elements within the same group have the same
    Odpowiedź
    (B)
    number of valence electrons
  • 9
    Which of the following halogens is liquid at room temperature?
    Odpowiedź
    (C)
    Bromine
  • 10
    Rare gases are stable because they
    Odpowiedź
    (D)
    have octet structures
  • 11
    In the periodic table, alkaline earth metals can be found in group
    Odpowiedź
    (B)
    ll
  • 12
    In which of the following series are the atoms arranged in order of increasing ionization energy?
    Odpowiedź
    (C)
    O, F, Ne
  • 13
    Which of the following bond types is responsible for the high boiling point of water?
    Odpowiedź
    (D)
    Hydrogen bond
  • 14
    In metallic solid, the forces of attraction is between the mobile valence electrons and the
    Odpowiedź
    (D)
    positively charged nuclei
  • 15
    The bonds in crystalline ammonium chloride are
    Odpowiedź
    (C)
    ionic, covalent and dative
  • 16
    Which of the following elements is diatomic?
    Odpowiedź
    (B)
    Oxygen
  • 17
    Noble gas molecules are held together by
    Odpowiedź
    (A)
    van der Waals forces
  • 18
    Which of the following statements about nuclear reaction is correct? The reaction
    Odpowiedź
    (B)
    takes place inside the nucleus
  • 19
    Consider the reaction represented by the following equation: C\(_2\)H\(_2\) + yH\(_2\) → C\(_2\)H\(_6\). The value of y in the reaction is
    Odpowiedź
    (C)
    2
  • 20
    The volume of 0.25 moldm-3 solution of KOH that would yield 6.5g of of solid KOH on evaporation is (K = 39.0; o = 16.0; H = 1.00)
    Odpowiedź
    (A)
    464.30 cm3
  • 21
    The percentage by mass of calcium in Ca(OCI)2 is [Ca = 40.0; CI = 35.5; O = 16.0]
    Odpowiedź
    (A)
    28.0%
  • 22
    The gas law which describes the relationship between volume and temperature is
    Odpowiedź
    (B)
    Charles' law
  • 23
    Which of the following phenomenna lead to decrease in volume of a liquid in an open container?
    Odpowiedź
    (C)
    Evaporation
  • 24
    The pressure exerted by a gas is a function of the
    Odpowiedź
    (D)
    frequency of collision between gaseous molecules
  • 25
    Which of the following gases are arranged in increasing order of diffusion rate? [H = 1 .0; C = 12; N = 14; O = 16; S = 32]
    Odpowiedź
    (A)
    SO 2 O2, NH3 H2
  • 26
    Which of the following variables is a measure of the average kinetic energy of the molecule of a gas?
    Odpowiedź
    (C)
    Temperature
  • 27
    When heat is absorbed during a chemical reaction, the reaction is said to be
    Odpowiedź
    (B)
    endothermic
  • 28
    The aqueous solution which has pH > 7 is
    Odpowiedź
    (D)
    Na2CO3(aq)
  • 29
    Which of the following acids would readily react with CaCO3 to liberate CO2?
    Odpowiedź
    (B)
    H2SO4
  • 30
    Which of the following compounds crystallizes without water of crystallization?
    Odpowiedź
    (C)
    NaCI
  • 31
    A substance is said to be impure if
    Odpowiedź
    (A)
    its melting point range is wide
  • 32
    The following factors affect the solubility of a solid in a given solvent except
    Odpowiedź
    (C)
    pressure
  • 33
    Consider the reaction represented by the equation: N\(_2\)O\(_4\)(g) ⇌ 2NO\(_2\)(g) ; ∆H = + x kJmol-1
    What happens when the temperature is reduced at equilibrium?
    Odpowiedź
    (B)
    Concentration of N 2O4(g) increases.
  • 34
    Which of the following cells produce electrical energy from chemical reactions?
    l. Lead-acid battery ll. Dry cell III. Deniell cell IV Electrolytic cell
    Odpowiedź
    (B)
    l, ll, and III only
  • 35
    Consider the redox reaction as represented by the following equation: 12(aq) + 2S2O32-(aq) → 21-(aq) + S4O62-(aq). Which of the species in the equation is reduced?
    Odpowiedź
    (C)
    12(aq)
  • 36
    The separation of petroleum fractions depends on the differences in their
    Odpowiedź
    (D)
    boiling points
  • 37
    The major product formed by the reaction between ethanoic acid and aqueous sodium hydroxide is
    Odpowiedź
    (B)
    sodium ethanoate
  • 38
    Which of the following organic compounds would decolourize bromie water?
    Odpowiedź
    (A)
    Benzene
  • 39
    How many isomers has C\(_3\)H\(_6\)CI\(_2\)?
    Odpowiedź
    (C)
    4
  • 40
    Which of the following reactions is common to all hydrocarbones?
    Odpowiedź
    (A)
    Combustion
  • 41
    A hydrocarbon compound contains 92.3% carbon Determine its empirical formula [H = 1.00; C = 12.0]
    Odpowiedź
    (A)
    CH
  • 42
    The main function of limestone in the blast furnace is to
    Odpowiedź
    (C)
    remove impurity
  • 43
    Which of the following raw materials is used in a plastic industry?
    Odpowiedź
    (A)
    Ethene
  • 44
    Which of the following statements about fine chemical is correct? It
    Odpowiedź
    (C)
    is produced in relatively small amount
  • 45
    Which of the following materials is classified as a non-biodegradable pollutant?
    Odpowiedź
    (C)
    Plastic