Thursday, 28 February 2019


jamb past questions and answers on chemistry 2016

1.     An element X has twoin the ratio 1:3. The relative atomic mass of x would be __.
A.   20.5
B.   21.0
C.   21.5
D.   22.0

2.   200cm3 of oxygen diffuse through a porous plug in 50 seconds. How long, will 80cm3 of methane (CH4) take to diffuse through the same porous plug under the same conditions?
A.   40 sec
B.   20 sec
C.   14 sec
D.   7 sec

3.   Which of the following terms indicates the number of bonds that can be formed by an atom?
A.   oxidation number
B.   Valence
C.   Atomic number
D.   Electro-negativity
 jamb past questions and answers on chemistry 2016

4.   The diagram above represents an atom of __.
A.   magnesium
B.   helium
C.   chlorine
D.   neon

5.   Which of the following gases is the most dangerous pollutant?
A.   Hydrogen sulphide.
B.   Carbon Monoxide
C.   Sulphur(iv)oxide
D.   Carbon Dioxide

6.   A Side effect or Soft water is that __.
A.   It gives offensive taste
B.   excess calcium is precipitated
C.   it attacks lead contained in pipes
D.   it encourages the growth of bacteria.

7.   Farmlands affected by crude oil spillage can be decontaminated by __.
A.   adding acidic solutions
B.   using aerobic bacteria
C.   pouring water on the affected area
D.   burning off the oil from the area.

8.   Which of the following functional groups will give gas bubbles when treated with a saturated solution of sodium hydrogen trioxocarbonate(iv)?  jamb past questions and answers on chemistry 2016
9.   The oxidation state of Cr in K2Cr2O7 is __.
A.   +7
B.   +6
C.   +5
D.   4

10. 2Na2O2(s) + 2H2O(l) 4Na0H(s) +O2.
The substance that is oxidized in the reaction above is __.
A.   2Na202(s)
B.       NaOH(aq)
C.       H2O(l)
D.       O2(g)

jamb past questions and answers on chemistry 2016
Z in diagram above represents __.
A.   heat of reaction
B.   activation energy
C.   free energy
D.   entropy of reaction

12. The nucleus of an atom contains
A.   protons only
B.   neutrons only
C.   protons and electrons
D.   protons and neutrons

13. Which of the following does NOT happen when a Zinc rod is introduced into a solution of Copper(II)sulphate?
A.   Electrons flow towards the zinc rod
B.   The Zinc rod dissolves
C.   The temperature of the soil chances
D.   The blue colour of the solution gradually disappears.

14. Which of the following statements is correct during the electrolysis of a caustic soda solution using platinum electrodes?
A.   Oxygen gas is given off at the cathode
B.   Hydrogen gas is given off at the anode
C.   Sodium metal is deposited at the cathode
D.   Alkalinity at the cathode increases.

15. Which of the following statements is INCORRECT?
A.   Fractional distillation of crude petroleum will give the following hydrocarbon fuels in order of increasing boiling point.  Butane < Petrol < Kerosene
B.   H2C = CH2 will serve as a monomer in the preparation of polythene
C.   both but-i-ene and but-i-yne will decolourize bromine readily
D.   Calcium carbide will react with water to form any alkyne

16. The iron(iii)oxide impurity in bauxite can be removed by __.
A.   fractional crystallization in acid solution
B.   dissolution in sodium hydroxide and filtration
C.   extraction With concentrated ammonia and re-precipitation
D.   electrolysis of molten mixture

17. Aluminium is extracted commercially from its ore by
A.   heating aluminium oxide with coke in a furnace
B.   the electrolysis of fused aluminium oxide in cryolite
C.   treating cryolite with sodium hydroxide solution under pressure
D.   heating sodium aluminium silicate to a high temperature

18. Which of the following compounds gives a yellow residue when heated and also reacts with aqueous sodium hydroxide to give a white gelatinous precipitate soluble in excess sodium hydroxide solution?
A.   (NH4)2CO3
B.   ZnCO3
C.   Al2(SO4)3
D.   PbCO3

19. The least easily oxidized of the metals below is __.
A.   Cu
B.   Na
C.   Zn
D.   Al

20.Which of the following chlorides would exhibit the least ionic character?
A.       MgCl2
B.   CaCl2
C.   LiCl
D.   AlCl3

21. Which of the following CANNOT be obtained by fractional distillation of petroleum?
A.   Ether
B.   Methane
C.   Butane
D.   Hydrogen

22. Which of the following is used as an anti-knock in automobile engines?
A.   tetramethylsilane
B.   leadtetraethyl
C.   Glycerol
D.   n-heptane

23. The Avogadro number of 24g of magnesium is the same as that of __.
A.   1g of hydrogen molecules
B.   16g of oxygen molecules
C.   32g of Oxygen molecules
D.   35.5g of chlorine molecules.

24. In an electrolyte set-up to protect iron from corrosion, the iron is __.
A.   made the cathode
B.   made the anode
C.   used with a metal of lower electro-positive potential
D.   initially coated with tin

25. The removal of rust from iron by treatment with tetraoxosulphate (vi) acid is based on the __.
A.   hydrolysis of the iron
B.   reaction of acid with base
C.   oxidation of the rust
D.   dehydration of the iron.

26. The substance often used for vulcanization of rubber is __.
A.   Chlorine
B.   hydrogen peroxide
C.   Sulphur
D.   tetraoxosulphate (vi) acid

27. Metals of the first transition series have special properties which are different from those of groups I and II elements because they have partially filled.
A.   s-orbitals
B.   p-orbitals
C.   d-orbitals
D.   f-orbitals

28. A particle that contains 11 protons, 12 neutrons and 10 electrons is probably a __.
A.   Neutral non-metal
B.   metallic ion
C.   non-metallic ion
D.   neutral metal.

29. A catalyst increases the rate of a chemical reaction by providing a path that __.
A.   raises the activation energy
B.   increases the temperature
C.   lowers the activation energy
D.   increases the concentration

30. A metal M displaces Zinc from ZnCl2 solution. This shows that __.
A.   electrons flow from Zinc to M
B.   M is more electropositive than Zinc
C.   M is more electronegative than Zinc
D.   Zinc is more electropositive than M.

31. Calculate the quantity of electricity in coulombs required to liberate 10g of copper from a copper compound.
A.   32395.5
B.   30156.3
C.   60784.5
D.   15196.6
[Cu 64    F = 96500c]

32. The IUPAC names for the compounds CH3COOH and CH2 = CH2 are respectively __.
A.   acetic acid and ethane
B.   ethanoic- acid and ethene
C.   methanoic acid and ethylene
D.   ethanol and ethene.

33. The boiling point of water is higher than that of methanol because __.
A.   water is an oxide while methanol is an alcohol
B.   inter-molecular forces in water are stronger than those in methanol
C.   Water is an inorganic compound while methanol is organic
D.   Water is a compound while methanol is a covalent compound

34. If an element x of atomic number Z and mass number y is irradiated by an intense concentration of neutrons, the relevant nuclear equation is __.jamb past questions and answers on chemistry 2016

35. Which combination of the following statements is correct? 1. Lowering the activation energy 2. conducting the reaction in a gaseous state. 3. Increasing the temperature. 4. removing the products as soon as they are formed. 5. Powdering the reactant if solid
A.   1. 2 and 3
B.   1, 3 and 5
C.   2, 3 and 5
D.   3 and 4

36. An element with atomic number twelve is likely to be __.
A.   electrovalent with a valency of 1.
B.   electrovalent with a valency of 2.
C.   covalent with a valency of 2.
D.   covalent with valency of 4.

37. Which of the following physical properties decreases across the periodic Table?
A.   ionization potential
B.   Electron affinity
C.   Electro-negativity
D.   Atomic radius.

38. If a gas occupies a container of volume 146cm3 at 18c and 0.971 atm, its volume in cm3 at s.t.p is __.
A.   133
B.   146
C.   266
D.   292

39. 50cm3 of carbon(ii)oxide was exploded with 150cm3 of air containing 20% oxygen by volume, which of the reactants was in excess?
A.   Carbon(ii)oxide
B.   Carbon(iv)oxide
C.   Oxygen
D.   Nitrogen

40. The formula CH2O for ethanoic acid is regarded as its __.
A.   molecular formula
B.   general formula
C.   empirical formula
D.   Structural formula


1. C
2. C
3. B
4. A
5. D
6. C
7. A
8. B
9. B
10. A
11. A
12. D
13. A
14. D
15. D
16. B
17. B
18. B
19. C
20. D
21. D
22. B
23. C
24. D
25. D
26. C
27. C
28. B
29. C
30. B
31. D
32. B
33. B
34. B
35. B
36. B
37. D
38. A
39. C
40. C

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