JAMB - Chemistry (1995)

  • 1
    Chromatography is used to separate components of mixtures which differ in their rates of?
    პასუხი
    (B)
    migration
  • 2
    Which of the following is a example of a chemical change?
    პასუხი
    (B)
    Rusting of iron
  • 3
    The number of hydrogen ions in 4.9 g of tetraoxosulphate (IV) acid is?

    (S = 32, O =16, H = 1, Avogadro Number = 6.02 x 10\(^{23}\) )
    პასუხი
    (B)
    6.02 x 1022
  • 4
    What volume of oxygen will remain after reacting 8cm\(^3\) of hydrogen with 20cm\(^3\) of oxygen?
    პასუხი
    (D)
    16 cm3
  • 5
    A gas sample with an initial volume of 3.25 dm3 is heated and allowed to expand to 9.75 dm3 at constant pressure. What is the ratio of the final absolute temperature to the initial absolute temperature?
    პასუხი
    (A)
    3:1
  • 6
    Two cylinders A and B each contains 30 cm\(^3\) of oxygen and nitrogen respectively at the same temperature and pressure. If there are 5.0 moles of nitrogen, then the mass of oxygen is?
    პასუხი
    (D)
    160.0 g
  • 7
    A liquid begins to boil when?
    პასუხი
    (C)
    its vapour pressure equals the atmosphere pressure
  • 8
    A particle that contains 8 proton, 9 neutrons and 7 electrons could be written as?
    პასუხი
    (B)
    O+
  • 9
    In the oil drop experiment, Millikan determined the?
    პასუხი
    (C)
    charge of the electron
  • 10
    The ability of ionic solids is generally due to the?
    პასუხი
    (B)
    crystal lattice forces
  • 11
    Which of the following statements is FALSE about isotopes of the same element?
    პასუხი
    (D)
    They have the same atomic number but different umber of elelctrons
  • 12
    Helium is often used in observation balloons because it is?
    პასუხი
    (B)
    light and non-combustible
  • 13
    Deliquescent substances are also?
    პასუხი
    (C)
    hygroscopic
  • 14
    When plastics and packaging materials made from chloroethene are burnt in the open, the mixture of gases released into the atmosphere is most likely to contain?
    პასუხი
    (C)
    hydrogen chloride
  • 15
    The difference between colloides and and suspensions is brought out clearly by the fact that while colloids?
    პასუხი
    (D)
    do not settle out on standing, suspensions do
  • 16
    In general, an increase in temperature increases the solubility of a solute in water because?
    პასუხი
    (D)
    most solutes dissolve with absorption of heat
  • 17
    Neutralization involves a reaction between H3O+ and?
    პასუხი
    (B)
    OH-
  • 18
    In the process of silver-plating a metal M, the metal M is the?
    პასუხი
    (D)
    cathode and a direct current is used
  • 19
    How many moles of copper would be deposited by passing 3F of electricity through a solution of copper (II) tetraoxosulpohate (IV)?

    (F = 96 500 C mol-)
    პასუხი
    (C)
    1.5
  • 20
    2CL-(aq) → CI2(g) + 2e-(aq). The above half-cell reaction occuring at the anode during the electrolysis of dilute ZnCI2 solution is?
    პასუხი
    (B)
    oxidation
  • 21
    Which of the following is a redox reaction?
    პასუხი
    (B)
    2FeBr2(aq) + Br4(aq) → 2FeBr3(aq)
  • 22
    Cr\(_2\)O\(_7\)\(^{2-}\)(aq) + 14H\(^+\)(aq) + 6l\(^-\)(aq) → 2Cr\(^{3+}\)(aq) + 3l(g) + 7H\(_2\)O(I).
    The change in the oxidation number of oxygen in the equation above is?
    პასუხი
    (A)
    0
  • 23
    If an equilibrium reaction has ∆H < O, the reaction will proceed favorably in the forward reaction at?
    პასუხი
    (A)
    low temperatures
  • 24
    Which of the following processes leads to increase in entropy?
    პასუხი
    (C)
    Boiling a sample of water
  • 25
    Which of the following equilibria is shifted to the right as a result of an increase in pressure?
    პასუხი
    (B)
    2NO2(g) N2O4(g)
  • 26
    In the industrial production of hydrogen from natural gas, carbon (IV) oxide produced along with the hydrogen is removed by?
    პასუხი
    (A)
    washing with water under pressure
  • 27
    Sulphur exists in six forms in the solid state. This property is known as?
    პასუხი
    (B)
    allotropy
  • 28
    A gas that will turn orange potassium heptaoxodichromate (lV) solution to clear green is?
    პასუხი
    (A)
    sulphur (lV) oxide
  • 29
    Which of the following ions will give a white precipitate with aqueous NaOH and soluble in excess of the base?
    პასუხი
    (C)
    Zn2+
  • 30
    In the extraction of iron in the blast furnace, limestone is used to?
    პასუხი
    (D)
    remove impurities
  • 31
    Which of the following compounds will impart a brick-red colour to a non-luminious bunsen flame?
    პასუხი
    (C)
    CaCl2
  • 32
    Group 1 A metals are not found free in nature because they?
    პასუხი
    (D)
    are very reactive
  • 33
    CHCl3 + Cl2 → HCl + CCl4. The reaction above is an example of?
    პასუხი
    (B)
    a substitution reaction
  • 34
    Which of the following pairs has compounds that are isomers?
    პასუხი
    (A)
    Propanal and propanone
  • 35
    Aromatic and aliphatic hydrocarbons can be distinguished from each other by the?
    პასუხი
    (C)
    action of heat
  • 36
    The role of sodium chloride in the preparation of soap is to?
    პასუხი
    (B)
    separate the soap from glycerol
  • 37
    CxHY + 4O2 → 3CO2 + 2H2O. The hydrocarbon, CxHY, in the reaction above is?
    პასუხი
    (C)
    propyne
  • 38
    An example of a secondary amine is?
    პასუხი
    (B)
    di-butylamine
  • 39
    The relatively high boiling points of alkanols are due to?
    პასუხი
    (D)
    hydrogen bonding
  • 40

    USE THE SECTION OF THE PERIODIC TABLE ABOVE TO ANSWER THIS QUESTION.Which of the indicate an alkali metal and a noble gas respectively?

    პასუხი
    (D)
    G and L
  • 41
    USE THE SECTION OF THE PERIODIC TABLE ABOVE TO ANSWER THIS QUESTION.Which letter represents a non-metal that is a solid at room temperature?
    პასუხი
    (A)
    T
  • 42

    The arrangement above can be used for the collection of

    პასუხი
    (D)
    nitrogen
  • 43

    Use the diagram above to answer this question. The activation energy of the uncatalysed reaction is

    პასუხი
    (A)
    X
  • 44

    It can be deduced that the rate of the reaction?

    პასუხი
    (B)
    for path ll is higher than path l
  • 45

    The option above shows the PH changes for the titration of a

    პასუხი
    (B)
    weak acid versus strong base