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 1: If atom X with six electrons in its outermost shell combines with atom Y with one electron in its outermost shell to form an ionic compound, then? Options:
  A) six atoms of X will combine with one of Y
  B) two atoms of X will combine with six of Y
  C) one atom of X will combine with two of Y
  D) two atoms of X will combine with one of Y
  E) one atom of X will combine with six of Y
  Show Answer
  The correct answer is C .
• Question 2: Which of the following compounds is NOT the correct product formed when the parent metals is heated in air? Options:
  A) Calcium oxide (CaO)
  B) Sodium oxide (Na₂O)
  C) Copper (ll) oxide (CuO)
  D) Tri-iron tetroxide (Fe₃O₄)
  E) Aluminium oxide (Al₂O₃)
  Show Answer
  The correct answer is D .
• Question 3:

  Burning magnesium ribbon in air removes which of the following

  (i) oxygen (ii) nitrogen (iii) argon and (iv) carbon(iv)oxide?

  Options:
  A) i and iv only
  B) i, ii, iii and iv only
  C) i only
  D) i and ii only
  Show Answer
  The correct answer is C .
• Question 4: The volume of a given gas is V cm³P mm Hg. what is the new volume of the gas if the pressure is reduced to half at constant temperature Options:
  A) 4 V cm³
  B) 2 V cm³
  C) V/2 cm³
  D) V cm³
  Show Answer
  The correct answer is B .
• Question 5:

  

  The compound above exhibits

  Options:
  A) geometric isomerism
  B) optical isomerism
  C) structural isomerism
  D) positional isomerism
  Show Answer
  The correct answer is B .
• Question 6:

  When large hydrocarbon molecules are heated at high temperature in the presence of a catalyst to give smaller molecules, the process is known as

  Options:
  A) disintegration
  B) polymerization
  C) cracking
  D) degradation
  Show Answer
  The correct answer is C .
• Question 7: According to the kinetic theory an absence in temperature causes the kinetic energy of particles to Options:
  A) decrease
  B) increase
  C) remain constant
  D) be zero
  Show Answer
  The correct answer is D .
• Question 8: An amphoteric oxide is an? Options:
  A) amorphous oxide of a metal
  B) amorphous oxide of a non-mental
  C) oxide that is insoluble in water
  D) oxide that behaves both as a base as well as an acid
  E) oxide that loses its oxygen on sublimation
  Show Answer
  The correct answer is D .
• Question 9: A gas that is not associated with global warming is Options:
  A) CO₂
  B) SO₃
  C) CH₄
  D) H₂
  Show Answer
  The correct answer is A .
• Question 10: An element, E, has the electronic configuration 1s²2s²2p⁶3s²p³. The reaction of E with a halogen X can give? Options:
  A) EX₃ and EX₅
  B) EX₃ only
  C) EX₅ only
  D) EX₂ and EX₃
  Show Answer
  The correct answer is A .