Chemistry Exam Past Questions and Answers | JAMB, WAEC and NECO

Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.

• Question 1731: The enzyme used in the hydrolysis of starch to dextrin and maltose is Options:
  A) amylase
  B) diastatse
  C) invertase
  D) zymase
  Show Answer
  The correct answer is B .
• Question 1732: Which of the following allotrope of carbon is a constituent of a lead pencil? Options:
  A) Graphite
  B) Diamond
  C) Lampblack
  D) Soot
  Show Answer
  The correct answer is A .
• Question 1733: The IUPAC nomenclature of compound CH₃CH₂COOCH₂CH₃ is Options:
  A) propyl ethanoate
  B) ethyl butanoate
  C) ethyl propanoate
  D) methyl butanoate
  Show Answer
  The correct answer is C .
• Question 1734: The gasification of coke is used for the manufacture of Options:
  A) producer gas
  B) natural gas
  C) synthetic gas
  D) industrial gas
  E) artificial gas
  Show Answer
  The correct answer is A .
• Question 1735: Four elements W, X, Y and Z have atomic number 2,6,16 and 20 respectively. Which of these elements is a metal? Options:
  A) X
  B) W
  C) Z
  D) Y
  Show Answer
  The correct answer is C .
• Question 1736:

  The sulphide that is commonly used in coating electric fluorescent tubes is?

  Options:
  A) iron(ii)Sulphide
  B) tin(ii)sulphide
  C) Zinc Sulphide
  D) lead(iv) Sulphide
  Show Answer
  The correct answer is C .
• Question 1737:

  

  The compound above exhibits

  Options:
  A) Geometric isomerism
  B) Positional isomerism
  C) Structural isomerism
  D) Optical isomerism
  Show Answer
  The correct answer is D .
• Question 1738:

  Which of the following separation techniques can be employed in obtaining solvent from its solution?

  Options:
  A) Evaporation
  B) Distillation
  C) Filtration
  D) Precipitation
  Show Answer
  The correct answer is B .
• Question 1739: Alloys are best prepared by? Options:
  A) high temperature weilding of the metals
  B) electrolysis using the major metallic component as cathode
  C) reducing a mixture of the oxies of the elements
  D) cooling a molten mixture of the necessary elements
  Show Answer
  The correct answer is D .
• Question 1740: A gas that will turn orange potassium heptaoxodichromate (lV) solution to clear green is? Options:
  A) sulphur (ii) oxide
  B) hydrogen sulphide
  C) sulphide (lV) oxide
  D) hydrogen chloride
  Show Answer
  The correct answer is A .