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 1671: An element wil readily form an electrovalent compound if it electron configuration is Options:
  A) 2, 8, 1
  B) 2, 8, 4
  C) 2, 8, 8
  D) 2, 8, 5
  Show Answer
  The correct answer is A .
• Question 1672: Chlorine consisting of two isotopes of mass number 35 and 37 in the ratio 3:1 has an atomic mass of 35.5. Calculate the relative abundance of the isotopes of mass number 37 Options:
  A) 20
  B) 25
  C) 60
  D) 75
  Show Answer
  The correct answer is B .
• Question 1673: Which of the following is formed when maltose reacts with concentrated tetraoxosulphate (VI) acid ? Options:
  A) Carbon (IV) oxide
  B) Coal tar
  C) Charcoal
  D) Toxic fumes
  Show Answer
  The correct answer is C .
• Question 1674:

  The size (diameter) of five elements are in the order R < T < W < X < Y, Y being the largest. If each atom has an electron situated on its circumference, and neglecting other factors, which of the atoms will lose its electron most reluctantly?

  Options:
  A) R
  B) T
  C) W
  D) X
  E) Y
  Show Answer
  The correct answer is A .
• Question 1675: The pollutant that contributes to the depletion of the ozone layer is Options:
  A) CFCs
  B) NO₂
  C) SO₂
  D) CO
  Show Answer
  The correct answer is A .
• Question 1676:

  The densities of two gases, X and Y, are 0.5 g dm^-3 and 2.0 dm^-3 respectively.

  What is the rate of diffusion of X relative to Y?

  Options:
  A) 0.1
  B) 0.5
  C) 2.0
  D) 4.0
  Show Answer
  The correct answer is C .
• Question 1677: 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 1678: Oxyacetylene flame is used for iron-welding because it Options:
  A) Makes the iron metals solidify very quickly
  B) Combines with oxygen to give a pop sound
  C) Evolves a lot of heat when burnt
  D) Dissociates to produce carbon (IV) oxide and oxygen
  Show Answer
  The correct answer is C .
• Question 1679:

  The type of bonding in [Cu(NH${}_3$)${}^4$]${}^{2+}$ is 

  Options:
  A) coordinate
  B) electrovalent
  C) metallic
  D) covalent
  Show Answer
  The correct answer is A .
• Question 1680: The acid that is used to remove rust is Options:
  A) boric
  B) hydrochloric
  C) trioxonitrate (V)
  D) tetraoxosulphate (VI)
  Show Answer
  The correct answer is B .