ExamPlay Dark Logo
เข้าสู่ระบบ

WAEC - Chemistry (1994)

  • 1
    The components of universal indicator solution can best be separated by
    คำตอบ
    (A)
    chromatography
  • 2
    The number of replaceable hydrogen atoms in one acid indicates its
    คำตอบ
    (A)
    basicity
  • 3
    Catalytic hydrogenation of alkenes produces compounds with the general formula
    คำตอบ
    (C)
    CnH2n+2
  • 4
    A measure of the degree of disorder in a chemical system is known as the
    คำตอบ
    (D)
    entrophy
  • 5
    In any chemical reaction, the total mass of the products is always equal to that of the reactants. This is statement of the law of
    คำตอบ
    (B)
    conservation of matter
  • 6
    Which of the following is not a property of magnesium oxide?
    คำตอบ
    (E)
    Low binding energy
  • 7
    Which of the following would increase the rate of reaction of chips of a metal M as shown in the equation below? M(s) + 2HCI(aq) → MCI2(aq) + H2(g)
    คำตอบ
    (D)
    Grinding the metal into powder
  • 8
    The oxidation number of phosphorus in \(PO_4^{3-}\) is
    คำตอบ
    (E)
    +5
  • 9
    The number of atoms in 1.2g of carbon - 12 isotope is
    คำตอบ
    (B)
    6.02 x 1022
  • 10
    Tetraoxosulphate (lV) acid is described as strong acid because it is highly
    คำตอบ
    (E)
    ionized in water
  • 11
    The following will decolourize acidified potassium tetraoxomanganate (VII) solution except
    คำตอบ
    (C)
    pentane
  • 12
    Polyatomicity is illustrated by molecules of
    คำตอบ
    (A)
    sulphur
  • 13
    Calcium is usually extracted by the electrolysis of its
    คำตอบ
    (E)
    chloride
  • 14
    When naphthalene on heating changes from the solid state directly to the gaseous state it undergoes
    คำตอบ
    (B)
    sublimation
  • 15
    Which of the following occurs when an aqueous solution of sodium hydroxide is electrolysed using graphite electrodes?
    คำตอบ
    (C)
    Oxygen gas is produced at the anode
  • 16
    If the volume of a given mass of gas at 0oC is 27.3cm3, what will be the volume of the gas at 10oC, pressure remaining constant?
    คำตอบ
    (B)
    28.3cm3
  • 17
    Glucose can be obtained from starch by
    คำตอบ
    (C)
    hydrolysis
  • 18
    How many faradays of electricity are required to liberate 9g aluminium? (AI = 27)
    คำตอบ
    (C)
    1.0
  • 19
    When water is dropped on calcium carbide, the gaseous product is an
    คำตอบ
    (C)
    alkyne
  • 20

    Mg\(_2\) + 2HCI\(_{(aq)}\) → MgCI\(_{2(g)}\) + H\(_{2(g)}\).

    From the equation above what mass of hydrogen would be produced if 12.0 g of magnesium reacted completely with dilute hydrochloric acid? (H = 1, Mg = 24)

    คำตอบ
    (A)
    1.0g
  • 21
    The positive of an element in the Periodic Table is determined by
    คำตอบ
    (D)
    the number of protons in its atom
  • 22
    Which of the following electronic structures belongs to a noble gas?
    คำตอบ
    (C)
    1s22s22p63s23p6
  • 23
    In a chemical reaction, the reacting species possess energy of motion known as
    คำตอบ
    (D)
    kinetic energy
  • 24
    The following compounds will decompose on heating except
    คำตอบ
    (B)
    K2CO3
  • 25
    Which of the following reactions is accompanied by the first ionization energy of an element X?
    คำตอบ
    (D)
    X (g) → X+ (g) +e-
  • 26
    What is the molar of hydrogen sulphide gas in the reaction H2SO4(aq) + 3H2S(g) → 4S(s) + 4H2O (l)n represented by the following equation?
    คำตอบ
    (A)
    Reducing agent
  • 27
    Alkanols have unexpectedly high boiling points relative to their molar masses because of intermolecular
    คำตอบ
    (A)
    hydrogen bonding
  • 28
    Sodium chloride is used in the following processes except in the
    คำตอบ
    (A)
    treatment of polluted water
  • 29
    The gaseous product formed when ammonia is passed over heated copper (ll) oxide is
    คำตอบ
    (B)
    nitrogen
  • 30
    Which of the following is not a halogen?
    คำตอบ
    (A)
    Silicon
  • 31
    Which of the following is likely to have the highest degree of hardness?
    คำตอบ
    (E)
    Lime water
  • 32
    Study the reaction represented by the equation: Alkanol + Alkanoic acid + conc. H\(_2\)SO\(_4\) → Alkanoate + water.  The type of process involved in the reverse reaction is
    คำตอบ
    (C)
    hydrolysis
  • 33
    Destructive distillation of coal means
    คำตอบ
    (C)
    heating coal in the absence of air
  • 34
    When magnesium ribbon burns in air, the products are
    คำตอบ
    (C)
    magnesium oxide and steam
  • 35
    The following compounds contain the same type of bonds except
    คำตอบ
    (B)
    hydrogen chloride