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 1231:

  A synthetic rubber is obtained from the polymerization of

  Options:
  A) neoprene
  B) isoprene
  C) butandiene
  D) propylene
  Show Answer
  The correct answer is B .
• Question 1232: A mixture is different from a compound because Options:
  A) the properties of a compound are those of its individual constituents while those of a mixture differ from its constituents
  B) a mixture is always homogeneous while a compound is not
  C) the constituent of a compound are chemically bound together while those of a mixture are not
  D) a mixture can be represented by a chemical formula while a compound cannot
  Show Answer
  The correct answer is C .
• Question 1233: How many protons, neutrons and electrons respectively are present in the element 60/27 Co? Options:
  A) 27, 33 and 33
  B) 33, 27 and 27
  C) 27, 33, and 27
  D) 60, 33 and 60
  Show Answer
  The correct answer is C .
• Question 1234:

  What is the chemical structure of soap and detergent molecules?

  Options:
  A) Hydrophilic head and hydrophobic tail
  B) Hydrophilic head and hydrophilic tail
  C) Hydrophobic head and hydrophobic tail
  D) Hydrophilic tail and hydrophobic head
  Show Answer
  The correct answer is A .
• Question 1235: 200 cm³ of a gas at 25^oC exerts a pressure of 700 mmHg. Calculate its pressure if its volume increase 350 cm³ at 75^oC. Options:
  A) 342.53 mmHg
  B) 1430.54 mmHg
  C) 467.11 mmHg
  D) 400.00 mmHg
  Show Answer
  The correct answer is C .
• Question 1236: When temporary hard water is boiled for sometime in a kettle, the inner surface of the kettle becomes coated with a deposit of Options:
  A) calcium tetraoxosulphate(VI)
  B) calcium trioxocarbonate (IV)
  C) calcium hydrogentrioxocarbonate (IV)
  D) aluminium trioxocarbonate (IV)
  Show Answer
  The correct answer is B .
• Question 1237:

  Which of the following alkanes has a straight-chain structure?

  Options:
  A) Cyclopentane (C5H10)
  B) Isobutane (C4H10)
  C) 2 - methyl propane (C4H10)
  D) Pentane (C5H12)
  Show Answer
  The correct answer is D .
• Question 1238: The label on a reagent bottle containing a clear organic liquid dropped off.The liquid was neutral to litmus and gave a colourless gas with metallic sodium. The liquid must be an? Options:
  A) alkanoate
  B) alkaene
  C) alkanol
  D) alkane
  Show Answer
  The correct answer is C .
• Question 1239: Atomicity of ozone is Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is C .
• Question 1240: CH₃COOC₂H₅(1) + H₂O₍₁₎ ⇌ CH ₃COOH _(aq) + C ₂H ₅OH _(aq)The purpose of H⁺ in the reaction above is to Options:
  A) increase the yield of products
  B) maintain the solution at a constant PH
  C) increase the rate of the hydrolysis
  D) decrease the rate of the reverse reaction
  Show Answer
  The correct answer is A .