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 1941:

  5cm³ of a saturated solution of sodium chloride at 30°C gave, on careful evaporation, 1.95g of solid salt. The solubility of sodium chloride at 30°C?

  (Na = 23, Cl = 35.5)

  Options:
  A) 5.00 mole dm³
  B) 5.67 mole dm³
  C) 6.00 mole dm³
  D) 6.67 mole dm³
  E) 7.00 mole dm³
  Show Answer
  The correct answer is D .
• Question 1942: The process that occurs when two equivalent forms of a compound are in equilibrium is Options:
  A) Isotopy
  B) Resonance
  C) Isomerism
  D) Reforming
  Show Answer
  The correct answer is B .
• Question 1943: Pure solvents are obtained by Options:
  A) distillation
  B) condensation
  C) extraction
  D) evaporation
  E) desolution
  Show Answer
  The correct answer is A .
• Question 1944:

  P_(g) + Q_(g) ↔ 3R_(s) + S_(g) ΔH is negative

  Which of the following will increase the yield of R?

  Options:
  A) Using a larger close vessel
  B) Increasing the temperature
  C) Removing some S
  D) Adding a positive catalyst
  Show Answer
  The correct answer is C .
• Question 1945: The decarboxylation of ethanoic acid will produce carbon (IV)oxide and Options:
  A) methane
  B) ethane
  C) propane
  D) butane
  Show Answer
  The correct answer is A .
• Question 1946:

  Which of the following is an example of a primary cell?

  Options:
  A) Alkaline battery
  B) Nickel-cadmium battery
  C) Lead-acid battery
  D) Lithium-ion battery
  Show Answer
  The correct answer is A .
• Question 1947: Addition of an aqueous solution of a salt gives a white precipitate. The salt is likely to be a? Options:
  A) nitrate
  B) carbonate
  C) chloride
  D) sulphide
  Show Answer
  The correct answer is B .
• Question 1948: The reaction of an alkanol with an alkanoic acid in the presence of concentrated H₂SO₄ will produce an? Options:
  A) alkanal
  B) alkanoate
  C) alkanone
  D) alkyne
  Show Answer
  The correct answer is B .
• Question 1949: 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 1950:

  A chemical process in which there is a gain of electrons is known as?

  Options:
  A) Sublimation
  B) Reduction
  C) Oxidation
  D) Distillation
  Show Answer
  The correct answer is B .