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 1961: Which of the following statements is incorrect? Options:
  A) Calcium reacts with water to form calcium
  B) Magnesium reacts very slowly with water but faster with warm water
  C) Iron will not react with water in the absence of air
  D) Sodium reacts with water
  E) Copper reacts with steam
  Show Answer
  The correct answer is E .
• Question 1962: Which of these require crystallization most? Options:
  A) Drug making
  B) Cement making
  C) Paint making
  D) Perfume making
  Show Answer
  The correct answer is A .
• Question 1963:

  Beryllium and Aluminium have similar properties because they

  Options:
  A) are both metals
  B) belong to the same group
  C) belong to the same period
  D) are positioned diagonally to each other
  Show Answer
  The correct answer is D .
• Question 1964: The octane number of a fuel whose performance is the same as that of a mixture of 55 g of 2,2,4- trimethly pentane and 45 g of n-heptane is ? Options:
  A) 45
  B) 55
  C) 80
  D) 100
  Show Answer
  The correct answer is B .
• Question 1965:

  H${}^{+}$ + OH${}^{-}$ H${}_2$O

  The equation above illustrates

  Options:
  A) precipitation
  B) hydration
  C) hydrolysis
  D) neutralization
  Show Answer
  The correct answer is D .
• Question 1966:

  A compound contains 31.91% potassium, 28.93% chlorine and the rest oxygen. What is the chemical formula of the compound?

  [K = 39, Cl = 35.5, O = 16]

  Options:
  A) KClO₄
  B) KClO
  C) KClO₂
  D) KClO₃
  Show Answer
  The correct answer is D .
• Question 1967: Ethene is prepared industrially by Options:
  A) Reforming
  B) Polymerization
  C) Distillation
  D) Cracking
  Show Answer
  The correct answer is D .
• Question 1968:

  When a substance is oxidized, it

  Options:
  A) Loses electrons
  B) Gains oxygen atoms
  C) Gains electrons
  D) Loses protons (H+ ions)
  Show Answer
  The correct answer is A .
• Question 1969:

  What is the principal ore of iron, from which iron is extracted?

  Options:
  A) Calcite
  B) Bauxite
  C) Magnetite
  D) Hematite
  Show Answer
  The correct answer is D .
• Question 1970: 20 cm³ of 1.0 molar NH₄OH solution when neutralized with 20.05cm³ of 0.1 molar HCl liberated -102 joules of heat. Calculate the heat of neutralization of NH₄OH? Options:
  A) -51.O KJ mol^-
  B) +57.3 KJ mol^-
  C) +57.O KJ mol^-
  D) +51.0 KJ mol^-
  Show Answer
  The correct answer is A .