JAMB - Chemistry (2019)

  • 1
    A secondary alkanol can be oxidized to give an?
    Răspuns
    (A)
    alkanone
  • 2
    Which of the following will give a precipitate with an aqueous solution of copper (I) chloride?
    Răspuns
    (D)
    But-1-yne
  • 3
    The IUPAC name for CH\(_3\)CH\(_2\)COOCH\(_2\)CH\(_3\) is
    Răspuns
    (C)
    ethylpropanoate
  • 4
    A certain hydrocarbon on complete combustion at s.t.p produced 89.6dm\(^3\) of CO\(_2\) and 54g of water. The hydrocarbon should be?
    Răspuns
    (D)
    C\(_4\)H\(_6\)
  • 5
    2-methylprop-1-ene is an isomer of?
    Răspuns
    (C)
    but-2-ene
  • 6
    Hydrocarbons which will react with Tollen's reagent conform to the general formula
    Răspuns
    (C)
    C\(_n\)H\(_{2n - 2}\)
  • 7
    The IUPAC name of the compound CF\(_3\)CHBrCl is
    Răspuns
    (B)
    2-bromo-2-chloro-1,1,1-trifluoroethane
  • 8
    A synthetic rubber is not obtained from the polymerization of?
    Răspuns
    (D)
    hexane
  • 9
    Burning magnesium ribbon in air removes which of the following
    (i) oxygen (ii) nitrogen (iii) argon and (iv) carbon(iv)oxide?
    Răspuns
    (C)
    i only
  • 10
    Which of the following is the best starting material for the preparation of oxygen? Heating of trioxonitrate (v) with
    Răspuns
    (A)
    Pb
  • 11
    Which of the following metals is the most essential in the regulation of blood volume, blood pressure and osmotic equilibrium?
    Răspuns
    (C)
    Sodium
  • 12
    Which of the following alkaline earth metals react more spontaneously with water?
    Răspuns
    (D)
    Strontium
  • 13
    When chlorine water is exposed to bright sunlight, the following products are formed
    Răspuns
    (C)
    HCl\(_{(aq)}\) and O\(_2\)
  • 14
    Which process(es) is/are involved in the turning of starch iodide paper blue-black by chlorine gas?
    Răspuns
    (C)
    chlorine oxidizes the iodide ion to produce iodine which attacks the starch to give the blue-black color
  • 15
    Which of the following is a set of neutral oxides?
    Răspuns
    (A)
    N\(_2\)O, H\(_2\)O, CO
  • 16
    SO\(_3\) is not directly dissolved in water in the industrial preparation of H\(_2\)SO\(_4\) by the contact process because
    Răspuns
    (C)
    The reaction between SO\(_3\) and water is violently exothermic
  • 17
    Which of the following statements does not show Rutherford's account of Nuclear Theory? An atom contains a region
    Răspuns
    (D)
    which is very large and in which close to 98% of projectiles pass undeflected
  • 18
    Elements X and Y have electronic configurations 1s\(^2\)2s\(^2\)2p\(^4\) and 1s\(^2\)2s\(^2\)2p\(^6\)3s\(^2\)3p\(^1\) respectively. When they combine, the formula of the compound formed is
    Răspuns
    (C)
    Y\(_2\)X\(_3\)
  • 19
    By what amount must the temperature of 200cm\(^3\) of Nitrogen at 27°C be increased to double the pressure if the final volume is 150cm\(^3\) (Assume ideality)
    Răspuns
    (A)
    150°C
  • 20
    The combustion of carbon(II)oxide in oxygen can be represented by equation:
     2CO + O\(_2\) → 2CO\(_2\)
    Calculate the volume of the resulting mixture at the end of the reaction, if 50cm\(^3\) of carbon(ii)oxide was exploded in 100cm\(^3\) of oxygen
    Răspuns
    (B)
    125cm\(^3\)
  • 21
    When ammonia and hydrogen ion bond together to form ammonium ion, the bond formed is called
    Răspuns
    (D)
    covalent bond
  • 22
    Which of the following represents the kind of bonding present in ammonium chloride?
    Răspuns
    (C)
    ionic and covalent
  • 23
    Consider the reaction
    A\(_{(s)}\) + 2B\(_{(g)}\) → 2C\(_{(aq)}\) + D\(_{(g)}\)
    What will be the effect of a decrease in pressure on the reaction?
    Răspuns
    (C)
    rate of backward reaction will increase
  • 24
    For the general equation of the nature
    xP + yQ ⇌ mR + nS, the expression for the equilibrium constant is
    Răspuns
    (D)
    \(\frac{[R]^m[S]^n}{[P]^x[Q]^y}\)
  • 25
    Which of the following reactions is an oxidation process?
    Răspuns
    (B)
    2O\(^{2-}\) + 4e\(^-\) \(\to\) O\(_2\)
  • 26
    If acidified Potassium Dichromate(VI) (K\(_2\)Cr\(_2\)O\(_7\)) acts as oxidizing agent, color changes from
    Răspuns
    (B)
    orange to green
  • 27

    The heat of formation of ethene, C\(_2\)H\(_4\) is 50 kJmol\(^{-1}\), and that of ethane, C\(_2\)H\(_6\) is -82kJmol\(^{-1}\). Calculate the heat evolved in the process:

    C\(_2\)H\(_4\) + H\(_2\) \(\to\) C\(_2\)H\(_6\)

    Răspuns
    (B)
    -132kJ
  • 28
    Which of the following statements about catalyst is false?
    Răspuns
    (D)
    catalysts do not alter the mechanism of the reaction and never appear in the rate low
  • 29
    Which of the following does not support the fact that air is a mixture?
    Răspuns
    (D)
    none of the above
  • 30
    What technique is suitable for separating a binary solution of potassium chloride and potassium trioxochlorate (V)?
    Răspuns
    (A)
    Fractional crystallization
  • 31
    At 27°C, 58.5g of sodium chloride is present in 250cm\(^3\) of a solution. The solubility of sodium chloride at this temperature is?
    (molar mass of sodium chloride = 111.0gmol\(^{-1}\))
    Răspuns
    (A)
    2.0 moldm\(^{-3}\)
  • 32
    Which of the following properties increases from left to right along the period but decreases down the group in the Periodic Table?
    i. Atomic Number ii. Ionization energy  iii. Metallic character  iv. Electron affinity
    Răspuns
    (B)
    ii and iv only
  • 33
    The molecular shape and bond angle of water are respectively
    Răspuns
    (D)
    bent, 105°
  • 34

    Na\(_2\)CO\(_3\) + 2HCl \(\to\) 2NaCl + H\(_2\)O + CO\(_2\)

    The indicator most suitable for this reaction should have a pH equal to

    Răspuns
    (C)
    3
  • 35
    A radioactive nucleus has a half-life of 20 years, starting with 100,000 particles, how many particles will be left exactly at the end of 40 years
    Răspuns
    (C)
    25,000 particles
  • 36
    Which two gases can be used for the demonstration of the fountain experiment?
    Răspuns
    (C)
    HCl and NH\(_3\)
  • 37
    Which of the following pollutants will lead to the depletion of ozone layer?
    Răspuns
    (A)
    chlorofluorocarbon
  • 38
    Which of the following describes the chemical property of acids?
    Răspuns
    (D)
    Acid + X\(_n\)CO\(_3\) \(\to\) Salt + H\(_2\)O + CO\(_2\)
  • 39
    Which of the following pairs cannot be represented with a chemical formula?
    Răspuns
    (A)
    air and bronze
  • 40

    Consider the equation below:

    Cr\(_2\)O\(_7 ^{2-}\) + 6Fe\(^{2+}\) + 14H\(^{+}\) \(\to\) 2Cr\(^{3+}\) + 6Fe\(^{3+}\) + 7H\(_2\)O.

    The oxidation number of chromium changes from

    Răspuns
    (B)
    +6 to +3
  • 41
    Which of the following is a physical change?
    Răspuns
    (D)
    Freezing ice cream
  • 42
    In the reaction between sodium hydroxide and tetraoxosulphate (VI) solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralize 10cm\(^3\) of 1.25 molar tetraoxosulphate (vi) acid?
    Răspuns
    (D)
    50cm\(^3\)
  • 43
    Sulphur exists in six forms in the solid state. This property is known as
    Răspuns
    (B)
    Allotropy
  • 44
    In the reaction:
    M + N → P
    ΔH = +Q kJ

    Which of the following would increase the concentration of the product?
    Răspuns
    (C)
    Increasing the temperature
  • 45
    A compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen. If the molar mass of the compound is 180. Find the molecular formula.
    [H = 1, C = 12, O = 16]
    Răspuns
    (C)
    C\(_6\)H\(_{12}\)O\(_6\)
  • 46
    The IUPAC nomenclature of the compound
    H\(_3\)C - CH(CH\(_3\)) - CH(CH\(_3\)) - CH\(_2\) - CH\(_3\)
    Răspuns
    (B)
    2,3- dimethyl pentane
  • 47
    Which of the following gases contains the least number of atoms at s.t.p?
    Răspuns
    (D)
    7 moles of argon
  • 48
    What mass of magnesium would be obtained by passing a current of 2 amperes for 2 hours 30 mins, through molten magnesium chloride?
    [1 faraday = 96500C, Mg = 24]
    Răspuns
    (D)
    2.00g
  • 49
    Which important nitrogen-containing compound is produced in Haber's process?
    Răspuns
    (A)
    NH\(_3\)
  • 50
    Elements in the periodic table are arranged in the order of their
    Răspuns
    (A)
    atomic numbers
  • 51
    What volume of 0.100M sodium trioxonitrate (V) solution contains 5g of solute ?
    [Na = 23, N = 14, O = 16]
    Răspuns
    (C)
    0.588 litres
  • 52
    The two ions responsible for hardness in water are
    Răspuns
    (A)
    Ca\(^{2+}\) and / or Mg\(^{2+}\)
  • 53
    Which of the following could not be alkane?
    Răspuns
    (C)
    C\(_7\)H\(_{14}\)
  • 54
    The electronic configuration of element Z is 1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^1\). What is the formula of the compound formed between Z and tetraoxosulphate (VI) ion.
    Răspuns
    (D)
    Z\(_2\)(SO\(_4\))\(_3\)
  • 55
    The hybridization in the compound \(CH_3 - CH_2 - C \equiv H\) is
    Răspuns
    (A)
    sp\(^3\) and sp
  • 56
    The following are isoelectronic ions except
    Răspuns
    (C)
    Si\(^{2+}\)
  • 57

    Consider the reaction: A + 2B\(_{(g)} \rightleftharpoons \) 2C + D\(_{(g)}\) (\(\Delta\)H = +ve)

    What will be the effect of decrease in temperature on the reaction?

    Răspuns
    (A)
    Rate of backward reaction will increase
  • 58
    A cell shorthand notation can be written as A / A\(^+\) // B\(^{2+}\) /B. The double slash in the notation represents the 
    Răspuns
    (C)
    salt bridge
  • 59
    The shapes of water, ammonia, carbon (iv) oxide and methane are respectively
    Răspuns
    (B)
    angular, pyramidal, linear and tetrahedral
  • 60
    Which quantum divides shells into orbitals?
    Răspuns
    (C)
    Azimuthal
  • 61
    The oxidation state(s) of nitrogen in ammonium nitrite is/are
    Răspuns
    (A)
    -3, +3
  • 62
    Hydrogen bond is a sort of
    Răspuns
    (A)
    van der waals force
  • 63
    Methane is prepared in the laboratory by heating a mixture of sodium ethanoate with soda lime. The chemical constituent(s) of soda lime is/are
    Răspuns
    (A)
    Ca(OH)\(_2\) and NaOH
  • 64
    Which of the following sets of operation will completely separate a mixture of sodium chloride, sand and iodine?
    Răspuns
    (A)
    addition of water, filtration, evaporation to dryness and sublimation
  • 65
    200cm\(^3\) of 0.50mol/dm\(^3\) solution of calcium hydrogen trioxocarbonate (IV) is heated. The maximum weight of solid precipitated is
    Răspuns
    (A)
    10g
  • 66
    Which of the following conditions will most enhance the spontaneity of a reaction?
    Răspuns
    (A)
    \(\Delta\)H is negative and greater than T\(\Delta\)S
  • 67
    X is a substance which liberates CO\(_2\) on treatment with concentrated H\(_2\)SO\(_4\). A warm solution of X can decolorize acidified KMnO\(_4\). X is
    Răspuns
    (D)
    H\(_2\)C\(_2\)O\(_4\)
  • 68
    The velocity, V of a gas is related to its mass, M by (k = proportionality constant)
    Răspuns
    (B)
    V = \(\frac{k}{M^{\frac{1}{2}}}\)
  • 69
    The emission of two successive beta particles from the nucleus \(^{32} _{15} P\) will produce
    Răspuns
    (C)
    \(^{32} _{17}\)Cl
  • 70
    Hydrogen diffused through a porous plug
    Răspuns
    (C)
    four times as fast as oxygen
  • 71

    If the cost of electricity required to discharge 10g of an ion X\(^{3+}\) is N20.00, how much would it cost to discharge 6g of ion Y\(^{2+}\)?

    [1 faraday = 96,500C, atomic masses are X = 27, Y = 24]

    Răspuns
    (D)
    N9.00
  • 72
    The cost of discharging 6.0g of a divalent metal, X from its salt is ₦12.00. What is the cost of discharging 9.0g of a trivalent metal, Y from its salt under the same condition?
    [X = 63, Y = 27, 1F = 96,500C]
    Răspuns
    (C)
    N63.00
  • 73
    How many alkoxyalkanes can be obtained from the molecular formula C\(_4\)H\(_{10}\)O?
    Răspuns
    (D)
    3
  • 74
    The reaction \(2H_2 S + SO_2 \to 3S + 2H_2 O\) is
    Răspuns
    (D)
    a redox reaction in which SO\(_2\) is the oxidant and H\(_2\)S is the reductant
  • 75
    A solution X, on mixing with AgNO\(_3\) solution gives a white precipitate soluble in aqueous NH\(_3\), a solution Y, when also added to X, also gives a white precipitate which is soluble when heated solutions X and Y respectively contain
    Răspuns
    (C)
    Pb\(^{2+}\), Cl\(^-\)