JAMB - Chemistry (1985)

• 1

  X + Y = Z is an equilibrium reaction. The addition of a catalyst?

  پاسخ دهید

  (B)

  increases the rate of change in concentrations of X, Y and Z
• 2

  What is the formula of sodium gallate if gallium (Ga)shows an oxidation number of + 3?

  پاسخ دهید

  (D)

  NaGa(OH)₄
• 3

  If the ONLY pollutants found in the atmosphere over a city are oxides of nitrogen, suspended lead compounds. carbon monoxide and high levels of methane, the probable source(s) of the pollution must be?

  پاسخ دهید

  (B)

  combustion of coal and automobile exhaust
• 4

  A correct electrochemical series can be obtained from K, Na, Ca, Al, Mg, Zn, Fe, Pb, H, Cu, Hg, Ag, Au by interchanging?

  پاسخ دهید

  (A)

  Al and Mg
• 5

  A certain industrial process is represented by the chemical equation 2A_(g) + B_(g) \(\to\) C_(g) + 3D_(g) \(\Delta\)H = X kJmol^-1. Which of the following conditions will favour the yield of the products?

  پاسخ دهید

  (A)

  increase in temperature, decrease in pressure
• 6

  2MnO^-₄ + 10Cl^- + 16H⁺ → 2Mn²⁺ + 5Cl₂ + 8H₂O. Which of the substances serves as an oxidizing agent?

  پاسخ دهید

  (D)

  MnO^-₄
• 7

  Which of the following metals will displace iron from a solution of iron(ll)tetraoxosulphate(lV)?

  پاسخ دهید

  (D)

  Zinc
• 8

  In the reaction H2(g)O \(\to\) H2(g) + 1/2O2(g)
  
  ΔH = -2436000 KJ, which of the following has no effect on the equilibrium position?

  پاسخ دهید

  (A)

  Adding argon to the system
• 9

  Complete hydrogenation of ethyne yields?

  پاسخ دهید

  (C)

  ethane
• 10

  Which of the following is used in the manufacture of bleaching powder?

  پاسخ دهید

  (B)

  Chlorine
• 11

  A man suspected of being drunk is made to pass his breath into acidified potassium dichlormate solution. If his breath carries a significant level of ethanol, the final colour of the solution is?

  پاسخ دهید

  (E)

  green
• 12

  When pollen grains are suspended in water and viewed through a microscope, they appear to be in a state of constant but erratic motion. This is due to?

  پاسخ دهید

  (E)

  the bombardment of the pollen grains by molecules of water
• 13

  The energy change (ΔH) for the reaction CO(g) + (1)/(2)O_2(g) → is?
  
  (ΔHi(CO) = -110.4 kJ mol^-) (ΔHi(CO₂) = -393 kJ mol^-)

  پاسخ دهید

  (C)

  -282.9 kJ
• 14

  Tetraoxosulphate (IV) ions are finally tested using?

  پاسخ دهید

  (B)

  acidified barium chloride
• 15

  An organic compound decolourized acidified KMnO₄ solution but failed to react with ammoniacal silver nitrate solution. The organic compound is likely to be?

  پاسخ دهید

  (C)

  an alkene
• 16

  Solid sodium hydroxide on exposure to air absorbs a gas and ultimately gives another alkaline substance with the molecular formula?

  پاسخ دهید

  (C)

  Na₂CO₃O
• 17

  Which of the following substances is the most abundant in the universe?

  پاسخ دهید

  (E)

  Hydrogen
• 18

  A colourless organic compound X was burnt in excess air to give two colourless and odourless gases, Y and Z, as products. X does not decolorize blue bromine vapour, Y turns lime milky while Z gives a blue colour with copper (ll) tetraoxosulphate (IV).
  Compound X is?

  پاسخ دهید

  (B)

  an alkane
• 19

  A colourless organic compound X was burnt in excess air to give two colourless and odourless gases, Y and Z, as products. X does not decolorize blue bromine vapour, Y turns lime milky while Z gives a blue colour with copper (ll) tetraoxosulphate (IV).
  Y and Z are respectively?

  پاسخ دهید

  (D)

  CO₂ and H₂O
• 20

  Which of the following compounds is NOT the correct product formed when the parent metals is heated in air?

  پاسخ دهید

  (D)

  Tri-iron tetroxide (Fe₃O₄)
• 21

  The atomic number of an element whose cation, X2+, has the ground state electronic configuration 1s22s22p63s22p6 is?

  پاسخ دهید

  (C)

  20
• 22

  When marble is heated to about 1473 K, another white solid is obtained which reacts vigorously with water to give an alkaline solution. The solution contains?

  پاسخ دهید

  (E)

  Ca(OH)₂
• 23

  Addition of dilute hydrochloride acid to an aqueous solution of a crystalline salt yield a yellow precipitate and a gas which turned dichromate paper green. The crystalline salt was probably?

  پاسخ دهید

  (C)

  Na₂S₂O₃.5H₂O
• 24

  The process involved in the conversion of an oil into margarine is known as?

  پاسخ دهید

  (A)

  hydrogenation
• 25

  An aqueous solution of an inorganic salt gave white precipitate (i) soluble in excess aqueous NaOH (ii) insoluble in excess aqueous NH\(_3\) (iii) with dilute HCl. The cation present in the inorganic salt is?

  پاسخ دهید

  (E)

  Pb₊₊
• 26

  Which of the following roles does sodium chloride play in soap preparation? It

  پاسخ دهید

  (D)

  separates the soap from the glycerol
• 27

  The function of sulphur during vulcanization rubber is to?

  پاسخ دهید

  (C)

  from chains which bind rubber molecules together
• 28

  

  Figure 1 above shows part of the periodic Table which of the elements belongs to the p-block?

  پاسخ دهید

  (D)

  P, Q and R
• 29

  

  The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. At room temperature (300 K)

  پاسخ دهید

  (A)

  Y is twice as soluble as X
• 30

  

  The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. If 80 g each of X and Y are taken up in 100 g of water at 353 K we shall have

  پاسخ دهید

  (B)

  only 16 g of Y undissolved
• 31

  

  The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. If the molar mass of X is 36 g, the number of moles of X dissolved at 343 K is

  پاسخ دهید

  (D)

  2.0 moles
• 32

  

  Use the above options to the question. The products formed on hydrolysis of

  پاسخ دهید

  (C)

  C
• 33

  

  The oxidation of

  پاسخ دهید

  (A)

  2-butanone
• 34

  

  The I.U.P.A.C name for the compound

  پاسخ دهید

  (D)

  4-methylpent-2-ene
• 35

  

  Use the following option above to answer this question. Which of the following is the functional group of carboxylic acids?

  پاسخ دهید

  (D)

  D
• 36

  Which of the following conduct electricity?

  پاسخ دهید

  (B)

  graphite
• 37

  An organic compound contains 72% carbon, 12% hydrogen and 16% oxygen by mass. The empirical formula of the compound is

  پاسخ دهید

  (D)

  C₆H₁₂O
• 38

  0.499g 0f CuSO₄.xH₂O when heated to constant weight gave a residue of 0.346g. the value of x is? (Cu = 63.5, S = 32.0, O = 16, H = 1)

  پاسخ دهید

  (D)

  4.0
• 39

  In the experiment, which of the following observations would suggest that a solid sample is a mixture? The

  پاسخ دهید

  (C)

  solid begins to melt at 573k but is not completely melted until 648k
• 40

  Hydrogen diffuses through a porous plug

  پاسخ دهید

  (E)

  four times as fast as oxygen
• 41

  Given that the molecular mass of iron is 56 and that of oxygen is 16, how many moles of iron(iii)oxide will be contained in 1kg of the compound?

  پاسخ دهید

  (C)

  6.25 moles
• 42

  3.0g of a mixture of potassium carbonate and potassium chloride were dissolved were dissolved in a 250cm\(^3\) standard flask. 25cm\(^3\)  of this solution required 40.00cm\(^3\) of 0.1M HCl for neutralization. What is the percentage by weight of K\(_2\)CO\(_3\) in the mixture ? (K = 39, O = 16, C = 12)

  پاسخ دهید

  (E)

  92
• 43

  Some properties of chemical substances are mentioned below... i. sour taste ii. slippery touch iii. yields alkaline gas with ammonium salt iv. has pH less than 7 v. turns phenolphthalein pink.
  
  Which of the above are NOT typical properties of alkalis?

  پاسخ دهید

  (C)

  i and iv
• 44

  A certain volume of gas at 298k is heated such that its volume and pressure are now four times the original values. What is the new temperature?

  پاسخ دهید

  (E)

  4768.0k
• 45

  Hydrogen is not liberated when trioxonitrate(v)acid reacts with zinc because

  پاسخ دهید

  (B)

  hydrogen produced is oxidized to water