WAEC - Chemistry (1993)

  • 1
    Copper metal will react with concentrated trioxonitrate (V) acid to give?
    Përgjigju
    (D)
    Cu(NO3)2 + 2NO2 + 2H2O
  • 2
    Which of the following separation is routinely applied in the petroleum industry
    Përgjigju
    (E)
    Fractional distillation
  • 3
    Starch undergoes complete hydrolysis to produce
    Përgjigju
    (D)
    glucose
  • 4
    Which of the following solids has a network structure?
    Përgjigju
    (A)
    Diamond
  • 5
    Trioxosulphate (lV) acid is not stored for a long period because it
    Përgjigju
    (C)
    is unstable and eaily decomposed
  • 6
    Alkanes are used mainly
    Përgjigju
    (B)
    as domestic and industrial fuels
  • 7
    Which of the following pairs illustrates isotopy?
    Përgjigju
    (D)
    Hydrogen and deuterium
  • 8
    Carbon is often deposited in the exhaust-pipe of cars because of the?
    Përgjigju
    (C)
    incomplete combustion of petrol
  • 9
    What does X atand for in the following expression? X = Log(10)(H+)
    Përgjigju
    (D)
    Degree of acidity (pH)
  • 10
    Sulphur burns in air to form
    Përgjigju
    (A)
    an acidic oxide
  • 11
    In which of the following changes is ∆S negative ?
    Përgjigju
    (A)
    H2O(l) → H2O(s)
  • 12
    Chlorine is is used in water treatment as
    Përgjigju
    (A)
    a germicide
  • 13
    Which of the following pieces of deposited if a current of 10A was passed through a solution of copper(ll) salt for 965 seconds? (1F = 96500 C)
    Përgjigju
    (C)
    0.05 mole
  • 14
    Some precious stones such as ruby and sapphire consist of aluminum oxide coloured by traces of the oxides of
    Përgjigju
    (C)
    transition metals
  • 15
    Consider the reaction represented by the following equation CaCI2 (aq) + H 2C2O 4(aq) ⇌ CaC 2O4(s) + 2HCI(aq). Which of the following would dissolve the precipitate of CaC 2O4 formed?
    Përgjigju
    (D)
    Adding concentrated hydrochloric acid
  • 16
    The following gases decolorize bromine water except
    Përgjigju
    (A)
    C2H6
  • 17
    What volume of distilled water should be added to 400cm3 of 2.0 mole dm-3 \(H_{2}SO_{4}\) to obtain 0.20 mole dm-3 of solution>
    Përgjigju
    (D)
    3,600cm-3
  • 18
    Which of the following indicates the correct increasing order of oxidizing power of the halogens?
    Përgjigju
    (B)
    l < Br < CI < F
  • 19
    Which of the following substances is a peroxide?
    Përgjigju
    (A)
    Na2O2
  • 20
    The component of air that removed when air is bubbled into alkaline pyrogallol solution is
    Përgjigju
    (B)
    oxgyen
  • 21
    Which of the following will not affect the degree of hardness in a sample of temporarily hard water?
    Përgjigju
    (D)
    Filtration
  • 22
    Examples of polymers include the following except
    Përgjigju
    (E)
    glass
  • 23
    When the trioxonitrate (IV) salt of an alkali metal Y is heated, the formula of the residue is
    Përgjigju
    (B)
    YNO2
  • 24
    Which of the following compounds of tin is a strong reducing agent?
    Përgjigju
    (D)
    SnH4
  • 25
    In which of the following pairs are both substances deliquescent?
    Përgjigju
    (C)
    CaCI2 and NaOH
  • 26
    Producer gas is a mixture of
    Përgjigju
    (D)
    nitrogen and carbon (ll) oxide
  • 27
    An alkene may be converted to an alkane by
    Përgjigju
    (D)
    hydrogenation
  • 28
    Which of the following gases are diatomic except
    Përgjigju
    (B)
    helium
  • 29
    Which of the following is correct about the electrons in the 1s orbital? They
    Përgjigju
    (C)
    are closest to the nucleus
  • 30
    The product of the reaction between ethanol and excess acidified K\(_2\)Cr\(_2\)O\(_7\) is
    Përgjigju
    (C)
    ethanoic acid