JAMB - Chemistry (1991)

  • 1
    Which of the following can be obtained by fractional distillation?
    Одговорити
    (A)
    Nitrogen from liquid air
  • 2
    Which of the following are mixtures?
    i, Petroleum
    ii, Rubber latex
    iii. Vulcanizer's solution
    iv, Carbon (II)sulphide
    Одговорити
    (A)
    i, ii and iii
  • 3
    An iron ore is known to contain 70.0% Fe2O3. The obtain from 80kg of the ore is?

    (Fe = 56, O = 16)
    Одговорити
    (B)
    39.2 kg
  • 4
    In two separate experiments, 0.36g and 0.71g of chlorine combined with a metal X to give Y and Z respectively. An analysis showed that Y and Z contain 0.20g and 0.40g of X respectively. The data above represents the law of ?
    Одговорити
    (C)
    constant composition
  • 5
    30cm\(^3\) of oxygen at 10 atmospheres pressure is placed in a 20 cm\(^3\) container. Calculate the new pressure if temperature is kept constant?
    Одговорити
    (B)
    15.0 atm
  • 6
    Calculate the volume of carbon (IV)oxide measured at s.t.p, produced when 1 kg of potassium hydrogen trioxocarbonate (IV) is totally decomposed by heat?

    (G.M.V. at s.t.p 22.4 dm3, K = 39, O = 16, C = 12, H = 1)
    Одговорити
    (C)
    112 dm3
  • 7
    A given quantity of a gas occupies a volume of 228 cm3 at a pressure of 750mm Hg. What will be its volume at atmospheric pressure?
    Одговорити
    (B)
    225 cm3
  • 8
    A sample of a gas exerts a pressure of 8.2 atm when confined in a 2.93 dm3 container at 20°C. The number of moles of gas in the sample is?

    (R = 0.082 litre atm / deg mole)
    Одговорити
    (A)
    1.00
  • 9
    Atoms of element X (with 2 electrons in the outer shell). combine with atoms of Y (with 7 electrons in the outer shell). Which of the following statements is FALSE? The compound formed?
    Одговорити
    (A)
    has formula XY
  • 10
    The electronic configuration of an elements is 1s22s22p63s23p3. How many unpaired electrons are there in the element?
    Одговорити
    (C)
    3
  • 11
    The ions X- and Y+ are isoelectronic, each containing a total of 10 electrons.
    How many protons are in the nuclei of the neutral atoms of X and Y respectively?
    Одговорити
    (D)
    9 and 11
  • 12
    Which of the following represents the type of bonding present in ammonium chloride molecule?
    Одговорити
    (C)
    Ionic and dative covalent
  • 13
    Which of the following is arranged in order of increasing electronegativity?
    Одговорити
    (B)
    sodium, magnesium, aluminium, phosphorus, chlorine
  • 14
    A quantity of air was passed through a weighed amount of alkaline pyrogallol. An increase in the weight of the pyrogallol would result from the absorption of?
    Одговорити
    (D)
    oxygen
  • 15
    Which of the following ions is a pollutant in drinking water even in trace amounts?
    Одговорити
    (B)
    Hg2+
  • 16
    The solubility of copper (II) tetraoxosulphate (Iv) is 75g in 100g of water at 100°C and 25g in 100g of water at 30°C. What mass of the salt would crystallize, if 50g of copper (II) tetraoxosulphate (VI) solution saturated at 100°C were cooled to 30°C ?
    Одговорити
    (D)
    14.3
  • 17
    A sample of temporary hard water can be prepared in the laboratory by?
    Одговорити
    (B)
    saturating lime water with carbon (IV) oxide
  • 18
    A property of a colloidal dispersion which a solution does not have is?
    Одговорити
    (A)
    the Tyndall effect
  • 19
    50 cm\(^3\) of sulphur (IV) oxide, 800cm\(^3\) of ammonia, 450 cm\(^3\) of hydrogen chloride, 1.0 cm\(^3\)of Carbon(IV) oxide will respectively saturate 1.0 cm\(^3\) of water at 15°C. Which of the following is suitable for demonstrating the fountain experiment?
    Одговорити
    (C)
    Ammonia and hydrogen chloride
  • 20
    How many structural isomers can be written for the alkyl bromide, C4H9Br?
    Одговорити
    (B)
    4
  • 21
    What volume of CO2 at s.t.p would be obtained by reacting trioxocarbonate (IV) with excess acid?

    (G.M.V at s.t.p = 22.4 dm3)
    Одговорити
    (B)
    22.40 cm 3
  • 22
    If a current of 1.5 A is passed for 4.00 hours through a molten tin salt and 13.3g of tin is deposited, what is the oxidation state of the metal in the salt?

    (Sn = 118.7, F = 96500 C mol-1)
    Одговорити
    (B)
    2
  • 23
    Which of the following equimolar solutions, Na2CO3 Na2 SO
    4CI FeCI3 CH3COONa,
    have pH greater than 7?
    Одговорити
    (C)
    Na2CO3 and CH3COONa
  • 24
    MnO-4 + 8H+ + ne → Mn++ + 4H2O. Which is the value of n in the reaction above?
    Одговорити
    (D)
    5
  • 25
    2H2S(g) + SO2(g) → 3S(s) + 2H2O(I). The above reaction is?
    Одговорити
    (B)
    a redox reaction in which SO2 is the oxidant and H2S is the reductant
  • 26
    Magnesium (IV) oxide is known to hasten the decomposition of hydrogen peroxide. Its main action is to?
    Одговорити
    (C)
    lower the activation energy for the reaction
  • 27
    1.1 g of CaCI2 dissolved in 50 cm3 of water caused a rise in temperature of 3.4°C. The heat of reaction, ∆H for CaCI2 in kj per mole is?

    (Ca = 40, CI = 35.5, specific heat of water is 4.18 jk-1)
    Одговорити
    (A)
    -71.1
  • 28
    NO(g) + CO(g) ↔ (1)/(2)N2(g) + CO2(g) ∆H = 89.3 kj.
    What conditions would favour maximum conversion of nitrogen (II) oxide and carbon (II) oxide in the reaction above?
    Одговорити
    (A)
    Low temperature and high pressure
  • 29
    Which of the following equilibria is unaffected by a pressure change?
    Одговорити
    (B)
    H 2(g) + I2(g) ↔ 2HI(g)
  • 30
    Which of the following gases will rekindle a brightly glowing splint?
    Одговорити
    (C)
    N2O
  • 31
    Which of the following salts can be melted without decomposition?
    Одговорити
    (A)
    Na2CO3
  • 32
    Oxygen gas can be prepared by heating?
    Одговорити
    (C)
    potassium trioxonitrate (V)
  • 33
    Addition of aqueous ammonia to a solution of Zn++ gives a white precipitate which dissolves in an excess of ammonia because?
    Одговорити
    (C)
    zinc forms a complex which is readily soluble in excess ammonia
  • 34
    Which of the following, in clear solution, forms a white precipitate when carbon (IV) oxide is bubbled into it for a short time?
    Одговорити
    (C)
    Ca(OH)2
  • 35
    Which of the following metals can be prepared in samples by the thermal decomposition of their trioxonitrate (V) salts?
    Одговорити
    (C)
    Mercury and silver
  • 36
    Copper (II) tetraoxosulphate (IV) is widely used as a?
    Одговорити
    (B)
    fungicide
  • 37
    Which of the following compounds can exist as geometric isomers?
    Одговорити
    (B)
    But-2-ene
  • 38
    How many grams of bromine will be required to completely react with 10 g of propyne?

    (C = 12, H = 1, Br = 80)
    Одговорити
    (D)
    80 g
  • 39
    Ethene when passed into concentrated H2SO4 is rapidly absorbed. The product is diluted with water and then warmed to produce?
    Одговорити
    (A)
    ethanol
  • 40
    One advantages of detergents over soap is that detergents?
    Одговорити
    (C)
    form soluble salts with hard water
  • 41
    A certain liquid has a high boiling point. It is viscous, non-toxic, miscible with water being very hygroscopic. This liquid is most likely to be?
    Одговорити
    (D)
    CH2OHCHOHCH2OH
  • 42



    Is known as?

    Одговорити
    (B)
    1-chloro-2-methylpropane
  • 43
    Which of the following statements is TRUE of the complete hydrolysis of a glycerine by sodium hygroxide?
    Одговорити
    (A)
    3 moles ofNaOH are required for each mole of glyceride
  • 44
    Which of the following are the products of the reaction between CH3COOH and CI2 in sunlight?
    Одговорити
    (A)
    CICH2COOH + HCI
  • 45
    Which of these is an acid salt?
    Одговорити
    (C)
    NaHS