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 1011: The gas that is the most dangerous pollutant to human is Options:
  A) sulphur (IV) oxide
  B) carbon (IV) oxide
  C) nitrogen (II) oxide
  D) hydrogen sulphide
  Show Answer
  The correct answer is D .
• Question 1012: In the chemical reaction A + B $\to$ C + D, more of D is formed? Options:
  A) if the concentrated of A is reduced
  B) if the concentrated of B is reduced
  C) if the concentrated of C is reduced
  D) if the concentration of C is increased
  E) if D is continuously removed from the reaction mixture
  Show Answer
  The correct answer is E .
• Question 1013: When sodium chloride and metallic sodium are each dissolved in water Options:
  A) both processes are exothermic
  B) both processes are endothermic
  C) the dissolution of metallic sodium is endothermic
  D) the dissolution of metallic sodium is exothermic
  E) the dissolution of sodium chloride is explosive
  Show Answer
  The correct answer is D .
• Question 1014: The leachate of a certain ash is used in local soap because it contain Options:
  A) sodium chloride and potassium hydroxide
  B) sodium hydroxide
  C) potassium hydroxide
  D) soluble carbonates and hydrogen carbonate
  Show Answer
  The correct answer is B .
• Question 1015: Which of the following hydrocarbons is mainly used as fuel? Options:
  A) Methylene
  B) Ethylene
  C) Methane
  D) Ethyne
  Show Answer
  The correct answer is C .
• Question 1016:

  A gas occupies a volume of 1.5 liters at a pressure of 2 atmospheres. If the pressure is increased to 4 atmospheres while the temperature remains constant, what will be the new volume of the gas?

  Options:
  A) 6 liters
  B) 1.5 liters
  C) 0.75 liters
  D) 3 liters
  Show Answer
  The correct answer is C .
• Question 1017: The general formula of an alkyl halide (where X represents the halide) is? Options:
  A) C_nH_2n2X
  B) C_nH_2n + ₁X
  C) C_nH_2n + ₂X
  D) C_nH_2nX
  Show Answer
  The correct answer is B .
• Question 1018: The best treatment for a student who accidentally poured concentrated tetraoxosulphate (VI) acid on his skin in the laboratory is to wash the skin with? Options:
  A) cold water
  B) sodium hydroxide solution
  C) iodine solution
  D) sodium trioxocarbonate (IV) solution
  Show Answer
  The correct answer is B .
• Question 1019:

  An element having the atomic number 17 will resemble which of the following elements having atomic number as given below?

  Options:
  A) 33
  B) 35
  C) 18
  D) 19
  Show Answer
  The correct answer is B .
• Question 1020:

  In a reaction: SnO + 2C → Sn + 2CO, the mass of coke containing 80% carbon required to reduce 0.302 kg of pure tin oxide is?

  (Sn - 119, O - 16, C - 12).

  Options:
  A) 0.40 kg
  B) 0.20 kg
  C) 0.06 kg
  D) 0.04 kg
  Show Answer
  The correct answer is C .