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 1481:

  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 1482:

  Which of these alloys contains copper?

  Options:
  A) solder
  B) steel
  C) permallory
  D) bronze
  Show Answer
  The correct answer is D .
• Question 1483: The substance ZnO dissolves in sodium hydroxide solution and mineral acid solution to give soluble products in each case. ZnO is therefore referred to as Options:
  A) an allotropic oxide
  B) an amphoteric oxide
  C) a peroxide
  D) a dioxide
  Show Answer
  The correct answer is B .
• Question 1484: Catalytic hydrogenation of benzene produces? Options:
  A) an aromatic hydrocarbon
  B) margarine
  C) cyclohexane
  D) D.D.T
  Show Answer
  The correct answer is C .
• Question 1485: Which of the following conduct electricity? Options:
  A) sulfur
  B) graphite
  C) diamond
  D) red phosphorus
  E) yellow phosphorus
  Show Answer
  The correct answer is B .
• Question 1486: An example of oxidation - reduction enzyme is Options:
  A) amylase
  B) protease
  C) lipase
  D) dehydrogenase
  Show Answer
  The correct answer is D .
• Question 1487:

  N₂O_4(g) ↔ 2NO_2(g) ΔH = +ve

  In the reaction above, an increase in temperature will

  Options:
  A) increase the value of the equilibrium constant
  B) decreases the value of the equilibrium constant
  C) increase in the reactant production
  D) shift the equilibrium to the left
  Show Answer
  The correct answer is A .
• Question 1488: Which of the following reactions is correct as as written? Options:
  A) FeCl₂ + 3NH₄OH → Fe(OH)₃ + 3NH₄Cl
  B) Pb₂O₃ + 4HCl → PbCl₂ + 2H₂O
  C) PbNO₃ + H₂S → PbS + 2HNO₃
  D) NaOH + H₂SO₄ → NaHSO₄ +H₂O
  E) 2NH₄NO₃ → N₂ + 2H₂O
  Show Answer
  The correct answer is D .
• Question 1489: The weakest attractive force that can be observed between two molecules is Options:
  A) ionic
  B) covalent
  C) coordinate covalent
  D) van der Waals
  Show Answer
  The correct answer is D .
• Question 1490:

  200cm³ each of 0.1M solutions of lead (II) trioxonitrate (V) and hydrochloric acid were mixed. Assuming that lead (II) chloride is completely insoluble, calculate the mass of lead (II) chloride that will be precipitated.

  [Pb = 207, Cl= 35.5, N = 14, O = 16]

  Options:
  A) 2.78g
  B) 5.56g
  C) 8.34g
  D) 11.12g
  Show Answer
  The correct answer is B .