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JAMB - Chemistry (2020)

  • 1
    The electronic configuration of an element is 1S\(^2\) 2S\(^2\) 2P\(^6\) 3S\(^2\) 3P\(^3\). How many unpaired electrons are there in the element?
    پاسخ دهید
    (C)
    3
  • 2
    Which of the following can be obtained by fractional distillation? 
    پاسخ دهید
    (A)
    Nitrogen from liquid air
  • 3
    Duralumin consists of aluminum, copper?
    پاسخ دهید
    (D)
    Manganese and Magnesium
  • 4
    An example of a polysaccharide is?
    پاسخ دهید
    (D)
    Starch
  • 5
    8g of CH\(_4\) occupies 11.2 at S.T.P. What volume would 22g of CH\(_3\)CH\(_2\)CH\(_3\) occupy under the same condition?
    پاسخ دهید
    (B)
    11.2dm\(^3\)
  • 6
    The best treatment for a student who accidentally poured conc tetraoxosulphate(vi) on his skin in the laboratory is to wash his skin with?
    پاسخ دهید
    (A)
    with cool running water
  • 7

    Which of the gas laws does this graph illustrate?

    پاسخ دهید
    (B)
    Charles
  • 8
    What are the possible oxidation numbers of an element if its atomic number is 17?
    پاسخ دهید
    (A)
    -1 and 7
  • 9
    What process would coal undergo to give coal gas, coal tar, ammoniacal liquor and coke?
    پاسخ دهید
    (B)
    Destructive distillation
  • 10
    Liquid black soap is made by boiling palm oil with liquid extract of ash. The function of the ash is to provide the ?
    پاسخ دهید
    (C)
    Alkali
  • 11
    When water drops are added to calcium carbide in a container and the gas produced is passed through a jet and lighted, the resultant flame is called an?
    پاسخ دهید
    (C)
    Oxyacetylene flame
  • 12
    Which of the following substances is a mixture?
    پاسخ دهید
    (B)
    Seawater
  • 13
    If the quantity of oxygen occupying 2.76L container at a pressure of 0.825 atm and 300k is reduced by one-half, what is the pressure exerted by the remaining gas?
    پاسخ دهید
    (A)
    1.650atm
  • 14
    Four elements P, Q, R and S have atomic numbers of 4, 10, 12 and 14 respectively. Which of these elements is noble gas? 
    پاسخ دهید
    (B)
    Q
  • 15
    The products of the thermal decomposition of ammonium trioxonitrate(v) are?
    پاسخ دهید
    (A)
    Nitrogen (I) Oxide and Water
  • 16
    How many valence electrons are contained in the element \(^{31}_{15}P\)?
    پاسخ دهید
    (A)
    3
  • 17

    The number of molecules of Carbon(iv)Oxide produced when 10.0g of CaCO\(_3\) is treated with 0.2dm\(^3\) of 1 Mole of HCL in the equation

    CaCO\(_3\) + 2HCL ⇒ CaCl\(_2\)  + H\(_2\) O + CO\(_2\)  , is?

    پاسخ دهید
    (C)
    6.02 X 10\(^{22}\)
  • 18
    The volume occupied by 1.58g of a gas at S.T.P is 500cm\(^3\). What is the relative molecular mass of the gas?  [ G.M.V at S.T.P = 22.4dm\(^{3}\) ]
    پاسخ دهید
    (D)
    71
  • 19
    Which of the following gases will rekindle a brightly splint?
    پاسخ دهید
    (C)
    N\(_2\)O
  • 20
    The shape of ammonia molecule is?
    پاسخ دهید
    (A)
    Trigonal planar
  • 21
    A few drop of conc HCL are added to about 10cm\(^3\) of a solution of PH 3.4. The PH of the resulting mixture is?
    پاسخ دهید
    (A)
    less than 3.4
  • 22
    Chromatography is used to separate components of mixture which differ in their rates of ?
    پاسخ دهید
    (B)
    migration
  • 23
    Deliquescent substances are also?
    پاسخ دهید
    (C)
    hygroscopic
  • 24
    Helium is used in observation of ballons because it is?
    پاسخ دهید
    (B)
    light and non-combustible
  • 25
    32g of anhydrous copper(ii)tetraoxosulphate(vi) dissolved in 1dm\(^3\) of water generated 13.0kj of heat. The heat solution is?
    پاسخ دهید
    (B)
    65.0kj/mol
  • 26

    A gaseous metallic chloride MCl consists of 20.22% of M by mass. The formula of the chloride is?

    [ M = 27, Cl = 35.5]

    پاسخ دهید
    (C)
    MCl\(_3\)
  • 27
    What quantity of electricity will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution?
    پاسخ دهید
    (B)
    48,250 C
  • 28
    Which of the following types of bonding does not involve the formation of new substances?
    پاسخ دهید
    (A)
    Metallic
  • 29
    An organic compound that does not undergo a reaction with both hydrogen cyanide and hydroxylamine can be?
    پاسخ دهید
    (A)
    Alkene
  • 30
    The substance often used for vulcanization of rubber is?
    پاسخ دهید
    (C)
    Sulphur
  • 31
    The chlorinated alkane often used industrially to remove grease is?
    پاسخ دهید
    (A)
    Tetrachloromethane
  • 32
    What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?
    پاسخ دهید
    (D)
    72.0g
  • 33
    Proteins in acid solution undergo?
    پاسخ دهید
    (C)
    Hydrolysis
  • 34
    The general formula for the Alkanals is?
    پاسخ دهید
    (B)
    RCHO
  • 35
    When cathode rays are deflected onto the electrode of an electrometer, the instrument becomes?
    پاسخ دهید
    (B)
    Negatively charged