WAEC - Chemistry (1996)

  • 1
    The existance of two or more forms of the same element in the same physical state is known as
    Хариулт
    (A)
    allotropy
  • 2
    When an atom gains an electron, it becomes 
    Хариулт
    (B)
    negatively charged
  • 3
    The alkali metals exhibit similar chemical properties because
    Хариулт
    (B)
    they have the same number of vallence electrons
  • 4
    What is the likely formula of compound formed between element M in group two and element X in group seven?
    Хариулт
    (D)
    MX2
  • 5
    ''Equal volumes of all gases at the same temperature and pressure contain the same number of molecules'' is an expression of
    Хариулт
    (C)
    Avogadro's Law
  • 6
    What volume of carbon (lV) oxide is produced at s.t.p. when 2.5g of CaCO3 reacts with excess acid according to the following equation? CaCO3 + 2HCI → CaCI2 +H2O + CO2 [CaCO3 = 100; molar volume of a gas at s.t.p = 22.4dm3]
    Хариулт
    (D)
    0.56dm3
  • 7
    A solution of pH 7 is
    Хариулт
    (B)
    neutral
  • 8
    Which of the following equations represents a neutralization reaction?
    Хариулт
    (C)
    H2SO4 + KOH → KHSO4 + H2 O
  • 9
    Amphoteric oxides are oxides which
    Хариулт
    (D)
    react with acids alkalis
  • 10
    The following acids are monobasic except
    Хариулт
    (D)
    tetraoxophosphorus (V) acid
  • 11
    An arrangement of two different metals in aqueous solutions of their salts to produce an electronic current is known as
    Хариулт
    (A)
    electrochemical cell
  • 12
    In which of the following compounds is the oxidation number of nitrogen equal to + 3?
    Хариулт
    (D)
    HNO2
  • 13
    Which of the following statements is not correct about electrolysis?
    Хариулт
    (A)
    Reduction occurs at the anode
  • 14
    Which of the following is not correct about a catalyst? It
    Хариулт
    (C)
    can start a chemical rection which will normally not take place
  • 15
    The rate of production of hydrogen gas from the reaction between zinc granules and hydrochloric acid can be increased by
    Хариулт
    (B)
    using zinc powder instead of zinc granules
  • 16
    What does X represent in the following equation? H 2(g) + 1/2O2(g) → H2O (l); ∆H = xKJ.
    Хариулт
    (E)
    Enthalpy of formation
  • 17
    If the third member of a homologous series is C3H8, the fifth member will be
    Хариулт
    (E)
    C5H12
  • 18
    Which of the following exhibits resonance?
    Хариулт
    (A)
    Benzene
  • 19
    On exposing palm wine to air for some days, it becomes sour owing to the conversion of
    Хариулт
    (C)
    ethanol to ethanoic acid
  • 20
    When acidified KMnO4 solution is decolorised by ethene, the gas acts as
    Хариулт
    (C)
    a reducing agent
  • 21
    What amount of hydrogen will be required for complete hydrogenation of one mole of pent-3-yne?
    Хариулт
    (B)
    2 moles
  • 22
    When excess carbon (lV) oxide is passed into lime water, the turbidity produced initially disappears due to the formation of
    Хариулт
    (C)
    calcium hydrogentrioxocarbonate (IV)
  • 23
    Which of the following is a disaccharide?
    Хариулт
    (D)
    sucrose
  • 24
    Use this following information to answer this question. Compound X was boiled with concentrated hydrochloric acid for a long time. One of the products was found to be a sugar. Compound X was probably
    Хариулт
    (D)
    cellulose
  • 25
    Use this following information to answer this question. Compound X was boiled with concentrated hydrochloric acid for a long time. One of the products was found to be a sugar. What type of reaction was involved between compound X and concentrated hydrochloric acid?
    Хариулт
    (C)
    Hydrolysis
  • 26
    The component of air that can be removed by alkaline pyrogallol solution is
    Хариулт
    (A)
    oxygen
  • 27
    During water treatment for town supply, water is passed through layers of send beds in order to
    Хариулт
    (B)
    filter the water
  • 28
    The cleansing action of soap in hard water is not satisfactory because soap
    Хариулт
    (A)
    forms insoluble calcium and magnesium salts
  • 29
    What is the role of MnO2 in the reaction represented by the following equation?MnO2 + 4HCI2 + CI2 + 2H2O
    Хариулт
    (B)
    Oxidizing agent
  • 30
    Nitrogen is prepared on a large scale by the
    Хариулт
    (A)
    fractional distillation of liquefied air
  • 31
    Ammonia gas is suitable for performing the 'Fountain' experiment because the gas is
    Хариулт
    (E)
    very soluble in water
  • 32
    Which of the following metals will be the most suitable for use where lightness and resistance to corrosion are of importance?
    Хариулт
    (E)
    Aluminium
  • 33
    What amount of copper is deposited when 13.0g of zinc reacts with excess copper (ll) tetraoxosulphate (IV) solution according to the following equation? Zn (s) + CuSO4(aq) → ZnSO4(aq) + Cu (s) [Cu =63,5, Zn = 65]
    Хариулт
    (B)
    0.2mole
  • 34
    The products formed when sodium hydrogen trioxocarbonate (IV) is heated strongly are
    Хариулт
    (E)
    sodium trioxocarbonate (IV) carbon (IV) oxide and steam
  • 35
    The following are properties of transition metals except
    Хариулт
    (E)
    low melting points