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 1141:

  At room temperature and standard pressure, chlorine gas is in which state of matter?

  Options:
  A) Plasma
  B) Solid
  C) Liquid
  D) Gas
  Show Answer
  The correct answer is D .
• Question 1142: If glucose is heated with concentration tetraoxosulphate (VI) acid, it will be dehydrated to Options:
  A) carbon
  B) carbon (IV) oxide
  C) ethene
  D) ethanol
  Show Answer
  The correct answer is A .
• Question 1143:

  Pure sulphuric acid is a liquid of 1:84 density. What volume of it would be required to prepare 250 cm³ of 2.0 M solution?

  (H = 1, S = 32, O = 16)

  Options:
  A) 2.00
  B) 2.66
  C) 3.00
  D) 3.66
  E) 4.00
  Show Answer
  The correct answer is B .
• Question 1144: Synthesis gas is a mixture of Options:
  A) CH₄ and H₂O
  B) CH₄ and H₂
  C) CO₂ and H₂
  D) CO and H₂
  Show Answer
  The correct answer is D .
• Question 1145: What is the percentage of sulphur in sulphur (IV) oxide? Options:
  A) 66%
  B) 25%
  C) 40%
  D) 50%
  Show Answer
  The correct answer is D .
• Question 1146:

  A metallic oxide which reacts with both HCl and NaOH to give salt and water only can be classified as __________.

  Options:
  A) an acidic oxide
  B) a basic oxide
  C) a neutral oxide
  D) an amphoteric oxide
  Show Answer
  The correct answer is D .
• Question 1147: 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 1148:

  

  The above diagram gives the potential energy profile of the catalyst and uncatalysed reactions of X_(g) + Y_(g) → XY_(g). Deduce the respective activation energies in KJ of the catalysed and uncatalysed reverse reactions: XY(g) → X_(g) + Y_(g)

  Options:
  A) 300, 500
  B) 500, 300
  C) -300, -500
  D) -500, -300
  Show Answer
  The correct answer is A .
• Question 1149: The soil around a battery manufacturing factory is likely to contain a high concentration of? Options:
  A) Ca²⁺ salts
  B) Pb²⁺ salts
  C) Mg²⁺ salts
  D) Al³⁺ salts
  Show Answer
  The correct answer is B .
• Question 1150: Which of the following statement is false? Options:
  A) Acids react with some metals, liberating hydrogen
  B) Acids react with carbonates, liberating carbondioxide
  C) Acids conduct electricity and are decomposed by the current, liberating hydrogen at the anode
  D) Acids have a sour taste
  E) Acids change the colour of indicators
  Show Answer
  The correct answer is C .