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Sunday, 14 June 2026
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Chemistry Past Questions and Answers

Jamb 1983 Chemistry Questions

Question 21:
Sodium sulphate decahydrate (Na2SO4.10 H2O) on exposure to air loses all its water of crystallization.
The process of loss is known as
  • A Efflorescence
  • B Hygroscopy
  • C Deliquescence
  • D Effervescence
  • E Dehydration
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Question 22:
Which of the following happens during the electrolysis of molten sodium chloride?
  • A Sodium ion loses an electron
  • B Chlorine atom gains an electron
  • C Chlorine ion gains an electron
  • D Sodium ion is oxidized
  • E Chloride ion is oxidized
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Question 23:
Crude petroleum pollutant usually seen on some Nigerian creeks and waterways can be dispersed or removed by
  • A Heating the affected parts in order to boil off the petroleum
  • B Mechanically stirring to dissolve the petroleum in water
  • C Pouring organic solvents to dissolve the petroleum
  • D Spraying the water with stergents
  • E Cooling to freeze out the petroleum
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Question 24:
An element is electronegative if
  • A It has a tendency to exist in the gaseous from
  • B Its ions dissolve readily in water
  • C It has a tendency to lose electrons
  • D It has a tendency to gain electrons
  • E It readily froms covalent bonds
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Question 25:
Solutions X, Y, and Z have PH values 3.0. 5. 0 and 9. 0 respectively. Which of the following statements is correct?
  • A All the solutions are acidic
  • B All the solutions are basic
  • C Y and Z are more acidic than water
  • D Y is more acidic than X
  • E Z is the least acidic
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