Chemistry JAMB, WAEC, NECO AND NABTEB Official Past Questions

799

Which of the following metals is the most essential in the regulation of blood volume, blood pressure and osmotic equilibrium?

  • A. Zinc
  • B. Manganese
  • C. Sodium
  • D. Iron
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800

Which of the following is the best starting material for the preparation of oxygen? Heating of trioxonitrate (v) with

  • A. Pb
  • B. Zn
  • C. Ca
  • D. Na
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801

Burning magnesium ribbon in air removes which of the following
(i) oxygen (ii) nitrogen (iii) argon and (iv) carbon(iv)oxide?

  • A. i and iv only
  • B. i, ii, iii and iv only
  • C. i only
  • D. i and ii only
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802

A synthetic rubber is not obtained from the polymerization of?

  • A. neoprene
  • B. isoprene
  • C. butandiene
  • D. hexane
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803

The IUPAC name of the compound CF\(_3\)CHBrCl is

  • A. 2-chloro-2-bromo-1,1,1-trifluoroethane
  • B. 2-bromo-2-chloro-1,1,1-trifluoroethane
  • C. 1-bromo-1-chloro-2,2,2-trifluoroethane
  • D. 1,1,1-trifluoro-2-bromo-2-chloroethane
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804

Hydrocarbons which will react with Tollen’s reagent conform to the general formula

  • A. C\(_n\)H\(_{2n}\)
  • B. C\(_n\)H\(_{2n + 2}\)
  • C. C\(_n\)H\(_{2n - 2}\)
  • D. C\(_n\)H\(_{2n + 1}\)OH
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805

2-methylprop-1-ene is an isomer of?

  • A. 3-methyl but-1-ene
  • B. 2-methyl but-1-ene
  • C. but-2-ene
  • D. pent-2-ene
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806

A certain hydrocarbon on complete combustion at s.t.p produced 89.6dm\(^3\) of CO\(_2\) and 54g of water. The hydrocarbon should be?

  • A. C\(_6\)H\(_6\)
  • B. C\(_4\)H\(_{10}\)
  • C. C\(_5\)H\(_{10}\)
  • D. C\(_4\)H\(_6\)
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807

The IUPAC name for CH\(_3\)CH\(_2\)COOCH\(_2\)CH\(_3\) is

  • A. methylpropanoate
  • B. ethylethanoate
  • C. ethylpropanoate
  • D. methylethanoate
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808

Which of the following will give a precipitate with an aqueous solution of copper (I) chloride?

  • A. But-2-ene
  • B. But-1-ene
  • C. But-2-yne
  • D. But-1-yne
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809

A secondary alkanol can be oxidized to give an?

  • A. alkanone
  • B. alkyne
  • C. alkanoic acid
  • D. alkanal
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810

(a) An element X is represented as \(^{40}_{20} X\)

(i) How many electrons and how many neutrons are present in the atom of X?

(ii) Write the electronic configuration of the atom

(b) Chlorine, whose atomic number is 17, reacts with the element X to form a compound.

(i) What type of bond is formed between X and chlorine?

(ii) Explain how the bond between X and chlorine is formed

(iii) Write the formula of the compound formed and statelhree properties of the compound.

(c) Chlorine has two isotopes of mass numbers 35 and 37 respectively. Suggest the possible relative molar masses of a chlorine molecule.

(d) Calculate the mass of one atom of carbon, given that one mole of carbon weighs 12.0g. (L = 6.02 x 10\(^{23}\))

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811

(a) Write the structural formula of:

(i) 2, 2, 4 – trimethylpentane, (ii) ethylmethanoate, (iii) trans 2, 3 – dimethylbut – 2-ene.

(b) Write the structure of the straight-chain compound that is isomeric with 2,2,4 – trimethylpentane.

(c) Write chemical equations to illustrate the oxidation of: (i) a secondary alkanol (ii) a dihydric alkanol.

(d) When-Crushed cassava was warmed with dilute hydrochloric acid, a sweet-tasting compound, D was obtained. When compcund D was treated with the enzyme, zymase and the mixture distilled a clear and colourleCsliduid, E was obtained. When liquid E was warmed with eth anoic acid i n the presence of a few drops of concentrated tetraoxosulphate (V1) acid, a compound F, with fruity smell was obtained

. (i)To what class of compounds does D belong?

(ii) Name E and F

(iii) Write the fun-ctional group in F

(iv) Write the equation for the reaction between E and ethanoic acid in the presence of concentrated tetraoxosulphate (VI) acid.

(v) Name the type of reaction that takes place between E and ethanoic acid.

(e) Arrange the followingcompounds in their correct order of increasing boiling points: CH\(_3\)CH\(_2\)CH\(_2\)OH, CH\(_3\)CH\(_2\)CH\(_2\)CH\(_2\)CH\(_2\)CH\(_3\) and CH\(_2\)CH\(_2\)CH\(_2\)CH\(_3\); Explain the order.

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812

(a) Explain why transition metals

(i) have high melting points

(ii) have variable oxidation states,

(iii) exhibit paramagnetism

 

(b) (i) Name the impurities present in bauxite

(ii) State how the impurities in bauxite are removed

(ii) Explain why aluminium oxide is said to be amphoteric.

 

(c) (i) Describe the electrolysis of copper (II) tetraoxosulphate (VI) solution, using copper electrodes.

(ii) Will the colour of the copper (II) tetraoxosulphate (VI) solution change at the end of the electrolysis described in (c)(i) above? Give reasons for your answer.

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813

(a) Explain with equation where appropriate, the functions of the following substances in the Solvay Process:

(i) limestone,

(ii) ammonia,

(iii) brine.

 

(b) Explain why the reaction between aqueous sodium trioxocarbonate (IV) solution and dilute hydrochloric acid is a neutralization reaction.

(c) Calculate the mass of sodium trioxocarbonate (IV) produced by the complete decomposition of 16.8g of sodium hydrogen trioxocarbonate (IV) (H = 1, O = 16, Na = 23, S = 33)

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814

State Gay-Lussac’s law and illustrate the law with one chemical reaction.

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815

Distinguish between cracking and reforming. Of what importance are the two processes in the petroleum industry?

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816

(a) Name the major raw materials used in the manufacture of the following:

(i) polythene

(ii) margarine

(iii) cement

(b) State one problem associated with oil producing areas

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817

 (a) What is a carbohydrate?

(b) Name two types of carbohydrates and give one example of each type

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818

(a) Write the ionic equation for the reaction between zinc powder and silver trioxonitrate (VI) solution

(b) Which substance in (a) above is (i) oxidized, (ii) reduced?

(c) State two applications of oxidation numbers

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819

(a) How does the collision theory explain the rate of a chemical reaction?
(b) State how each of the following affects the rates of chemical reactions:

(i) surface area (ii) catalyst

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