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 81: The relative atomic mass of a naturally occurring lithium consisting of 90% Li and 10% Li is Options:
  A) 6.9
  B) 7.1
  C) 6.2
  D) 6.8
  Show Answer
  The correct answer is C .
• Question 82:

  Which of the following statements is true regarding the melting and boiling points of pure substances?

  Options:
  A) The boiling point is always higher than the melting point
  B) The melting point is always higher than the boiling point
  C) The melting and boiling points are always the same for all substances
  D) The melting and boiling points can vary depending on the substance
  Show Answer
  The correct answer is D .
• Question 83: The salt formed from a weak acid and a strong base hydrolyzes in water to form Options:
  A) A saturated solution
  B) an acidic solution
  C) a buffer solution
  D) an alkaline solution
  Show Answer
  The correct answer is D .
• Question 84: Rare gases are suitable because they Options:
  A) are monoatomic
  B) form ions easily
  C) have duplet or octet electronic configuration in the outermost shells in their atoms
  D) are volatile gases
  Show Answer
  The correct answer is C .
• Question 85: Which of the following chloride would exhibit the least ionic character? Options:
  A) MgCl₂
  B) CaCl₂
  C) LiCl
  D) AlCl₃
  Show Answer
  The correct answer is D .
• Question 86: If a gas occupies a container of volume 146 cm³ at 18°C and 0.97`atm, its volume 146cm³ at s.t.p is? Options:
  A) 133
  B) 146
  C) 266
  D) 292
  Show Answer
  The correct answer is A .
• Question 87:

  A basic postulate of the kinetic theory of gases is that the molecules of a gas move in straight lines between collisions. This implies that

  Options:
  A) collisions are perfectly elastic
  B) forces of repulsion exist
  C) forces of repulsion and attraction are in equilibrium
  D) collisions are inelastic
  Show Answer
  The correct answer is B .
• Question 88:

  What happens to the position of equilibrium, if a reversible exothermic reaction is subjected to a decrease in temperature?

  Options:
  A) The position of equilibrium shifts to the left
  B) The position of equilibrium shifts to the right.
  C) The position of equilibrium remains unchanged
  D) The reaction stops
  Show Answer
  The correct answer is B .
• Question 89: Millikan's contributions to the development of atomic theory is the determination of Options:
  A) charge on electron
  B) positive rays
  C) charge to mass ratio
  D) cathode rays
  Show Answer
  The correct answer is A .
• Question 90: Arrange HCI, CH₃COOH, C₆H₅CH₃ in order of increasing conductivity. Options:
  A) HCI, CH₃COOH, C₆H₅CH₃
  B) C₆H₅CH₃, HCI, CH₃COOH
  C) C₆H₅CH₃, CH₃COOH, HCI
  D) CH₃COOH, C₆H₅CH₃, HCI
  Show Answer
  The correct answer is C .