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 1891:

  Which of the following is a characteristic property of acids?

  Options:
  A) Turn litmus paper blue
  B) Bitter taste
  C) pH value above 7
  D) React with metals to produce hydrogen gas
  Show Answer
  The correct answer is D .
• Question 1892: The process by which atoms are rearranged into different molecular structure in the petroleum refining process is referred to as Options:
  A) catalytic cracking
  B) hydrocracking
  C) polymerization
  D) reforming
  Show Answer
  The correct answer is D .
• Question 1893:

  If a reaction is exothermic and there is a great disorder, it means that

  Options:
  A) the reaction is static
  B) the reaction is in a state of equilibrium
  C) there will be a large increase in free energy
  D) there will be a large decrease in free energy
  Show Answer
  The correct answer is D .
• Question 1894: The combustion of ethene, C ₂H ₄, is given by the equation C ₂H ₄ + 30 ₂ → 2CO₂ + 2H₂ O; ∆H = - 1428 KJ. If the molar heats of formation of water and carbon (IV) oxide are - 286 kJ and - 396 kJ respectively, calculate the molar heat of formation of ethene in KJ Options:
  A) - 2792
  B) + 2792
  C) - 64
  D) + 64
  Show Answer
  The correct answer is D .
• Question 1895: A given mass of gas occupies 2dm³ at 300k. At what temperature will its volume be doubled, keeping the pressure constant? Options:
  A) 400k
  B) 480k
  C) 550k
  D) 600k
  Show Answer
  The correct answer is D .
• Question 1896: When ethene gas reacts with chlorine gas to form 1, 2-dichloroethene, the reaction is called? Options:
  A) substitution
  B) addition
  C) polymerization
  D) hydrolysis
  E) reduction
  Show Answer
  The correct answer is B .
• Question 1897: The most important use of hydrogen is in the Options:
  A) manufacture of ammonia
  B) manufacture of methyl alcohol
  C) manufacture of ethyl alcohol
  D) hydrogenation of oils
  Show Answer
  The correct answer is A .
• Question 1898: The arrangement of particles in crystal lattices can be studied using Options:
  A) X - rays
  B) γ - rays
  C) α - rays
  D) β - rays
  Show Answer
  The correct answer is A .
• Question 1899: In recharging a lead-acid accumulator, the reaction at the cathode can be represented as Options:
  A) Pb²⁺_(aq) + SO^2-_4(aq) →PbSO_4(s)
  B) Pb²⁺_(aq) + 2e^- →Pb_(s)
  C) Pb²⁺_(aq) + 2H₂O_(l) → PbO_2(s) + 4H⁺_(aq) + 4e^-
  D) Pb_(s) → Pb²⁺_(aq) + 2e^-
  Show Answer
  The correct answer is D .
• Question 1900:

  What is the IUPAC name for the compound CCl${}_4$?

  Options:
  A) Tetrahydrochloride
  B) Tetrachloromethane
  C) Carbon tetrachloride
  D) Chloroform
  Show Answer
  The correct answer is B .