JAMB - Chemistry (2017)

  • 1
    The general formula of alkanones is
    Відповідь
    (B)
    RCOR'
  • 2
    The constituent common to duralumin and alnico is
    Відповідь
    (C)
    Al
  • 3
    The shape of the S-orbital is
    Відповідь
    (D)
    spherical
  • 4
    Aluminium hydroxide is used in the dyeing industry as a
    Відповідь
    (D)
    mordant
  • 5
    The tincture of iodine means iodine dissolved in
    Відповідь
    (A)
    ethanol
  • 6
    Temporary hard water is formed when rain water containing dissolved carbon(IV) oxide flows over deposits of
    Відповідь
    (A)
    CaCO3
  • 7
    The acid anhydride that will produce weak acid in water is
    Відповідь
    (D)
    CO2
  • 8
    The process that occurs when two equivalent forms of a compound are in equilibrium is
    Відповідь
    (B)
    Resonance
  • 9
    In the laboratory preparation of ethyl ethanoate, the water present in the mixture is removed using ?
    Відповідь
    (A)
    Anhydrous CaCl2
  • 10
    The constituent of air necessary in the rusting process are
    Відповідь
    (A)
    O2 and H2O
  • 11
    For a general equation of the nature xP + yQ → mR + nS, the expression for the equilibrium constant is
    Відповідь
    (C)
    \(\frac{[R]^m [S]^n}{[P]^x [Q]^y}\)
  • 12
    A given mass of gas occupies 2dm3 at 300k. At what temperature will its volume be doubled, keeping the pressure constant?
    Відповідь
    (D)
    600k
  • 13
    The oxidation number of iodine in KIO3 is
    Відповідь
    (C)
    +5
  • 14
    An isomer of C5H12 is
    Відповідь
    (C)
    2–methyl butane
  • 15
    When few drops of concentrated trioxonitrate(V) acid is added to an unknown sample and wanned an intense yellow colouration is observed. The likely functional group present in the sample is
    Відповідь
    (A)
    NH2RCHCOOH
  • 16
    A sample of orange juice is found to have a PH of 3.80. What is the concentration of the hydroxide ion in the juice?
    Відповідь
    (B)
    6.3 \(\times\) 10-11
  • 17
    Incomplete oxidation of ethanol yields
    Відповідь
    (D)
    CH3CHO
  • 18
    The salt formed from a weak acid and a strong base hydrolyzes in water to form
    Відповідь
    (D)
    an alkaline solution
  • 19
    The ideal gas laws and equations are true for all gases at
    Відповідь
    (D)
    low pressure and high temperatures
  • 20
    When ΔH is negative, a reaction is said to be
    Відповідь
    (B)
    exothermic
  • 21
    \(^{226}_{88}Ra\) → \(^x_{86}Rn\) + alpha particle
    Відповідь
    (D)
    222
  • 22
    The shape of ammonia molecules is
    Відповідь
    (A)
    trigonal pyramidal
  • 23
    The mass of silver deposited when a current of 10A is passed through a solution of silver salt for 4830s is – (Ag = 108 F = 96500(mol-1)
    Відповідь
    (A)
    54.0g
  • 24
    Tin is unaffected by air at ordinary temperature due to its?
    Відповідь
    (B)
    Weak electropositive character
  • 25
    Calculate the amount in moles of silver deposited when 9650C of electricty is passed through a solution of silver salt [= 96500 Cmol-1]
    Відповідь
    (D)
    0.10
  • 26
    The reaction of halogens with alkanes in the presence of sunlight is an example of
    Відповідь
    (D)
    substitution reaction
  • 27
    The enzyme used in the hydrolysis of starch to dextrin and maltose is?
    Відповідь
    (B)
    amylase
  • 28
    The alkyl group is represented by the general formula
    Відповідь
    (C)
    CnH2n + 1
  • 29
    Cu\(_2\)S(g) + O\(_2\)(g) → 2Cu + SO\(_2\)(g)
    What is the change in the oxidation number of copper in the reaction?
    Відповідь
    (C)
    + 1 to 0
  • 30

    In the diagram above. X is

    Відповідь
    (B)
    SO2
  • 31

    The diagram above. Y is

    Відповідь
    (D)
    Concentrated H2SO4
  • 32
    Calculate the mass of copper deposited when a current of 0.5 ampere was passed through a solution of copper(II) chloride for 45 minutes in an electrolytic cell. [Cu = 64, F = 96500Cmol-1]
    Відповідь
    (D)
    0.448g
  • 33


    The IUPAC nomenclature of the structure above is

    Відповідь
    (B)
    2-methylbut-1-ene
  • 34
    The reddish–brown rust on iron roofing sheets consists of
    Відповідь
    (C)
    Fe2O3.XH2O
  • 35
    The densities of two gases, X and Y are 0.5gdm-3 and 2.0gdm-3 respectively. What is the rate of diffusion of X relative to Y?
    Відповідь
    (C)
    2.0
  • 36
    The carbon atoms on ethane are
    Відповідь
    (B)
    sp3 hybridized
  • 37
    According to Charle's law, the volume of a gas becomes zero at
    Відповідь
    (B)
    −273°c
  • 38
    An oxide XO2 has a vapour density of 32. What is the atomic mass of X?
    Відповідь
    (B)
    32
  • 39
    The gas that can be collected by downward displacement of air is
    Відповідь
    (D)
    ammonia
  • 40
    In the laboratory preparation of trioxonitrate (V) acid the nitrogen(iv) oxide formed as a by-product is removed by
    Відповідь
    (D)
    bubbling air through the acid solution
  • 41
    A particle that contains 9 protons, 10 neutrons and 10 electrons is
    Відповідь
    (D)
    negative ion
  • 42
    Ethene is prepared industrially by
    Відповідь
    (D)
    Cracking
  • 43
    Calculate the amount in moles of a gas which occupies 10.5 dm3 at 6 atm and 30oC [R = 0.082 atm dm3 K-1 mol-1]
    Відповідь
    (A)
    2.536
  • 44
    If 100cm3 of oxygen pass through a porous plug is 50 seconds, the time taken for the same volume of hydrogen to pass through the same porous plug is? [O = 16, H = 1]
    Відповідь
    (B)
    12.5s
  • 45
    Due to the high reactivity of sodium, it is usually stored under
    Відповідь
    (C)
    paraffin