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 741:

  Which organic compound is responsible for the characteristic aroma of fruits?

  Options:
  A) Alkane
  B) Alkyne
  C) Ester
  D) Amine
  Show Answer
  The correct answer is C .
• Question 742:

  Which of the following is an example of a chemical change?

  Options:
  A) dissolution of salt in water
  B) rusting of iron
  C) melting of ice
  D) separating a mixture by distillation
  Show Answer
  The correct answer is B .
• Question 743: Some properties of chemical substances are mentioned below... i. sour taste ii. slippery touch iii. yields alkaline gas with ammonium salt iv. has pH less than 7 v. turns phenolphthalein pink.Which of the above are NOT typical properties of alkalis? Options:
  A) i, iv and v
  B) iv and v
  C) i and iv
  D) ii and v
  E) ii, iii and iv
  Show Answer
  The correct answer is C .
• Question 744:

  

  The compound above is the product of the oxidation of

  Options:
  A) 2-methlbutan-2-ol
  B) 2-methylbutan -1- ol
  C) 2, 3-dimethylprop 1-ol
  D) Pentan -2- ol
  Show Answer
  The correct answer is B .
• Question 745:

  What is the molecular geometry of a molecule with three bonding pairs and no lone pairs around the central atom?

  Options:
  A) Tetrahedral
  B) Trigonal planar
  C) Linear
  D) Octahedral
  Show Answer
  The correct answer is B .
• Question 746: Which of the following is NOT correct test for the named organic compound in each case? Options:
  A) Butanoic acid solution gives effervescence with Na₂CO₃ solution
  B) Glucose when reacted with Na₂CrO₄ at 0°C will show immediate discharge of colour
  C) When but-2-ene is reacted with dilute solution of KMnO₄ the purple colour of KMnO is discharged readily even room temperature
  D) When butan-2-ol is boiled with butanoic acid with a drop of concentrated H₂SO₄ a sweet smelling liquid is produced
  Show Answer
  The correct answer is B .
• Question 747:

  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 748: The functional group present in an organic compound which gives bubbles on treatment with a saturated solution of NaHCO₃ is? Options:
  A) hydroxyl group
  B) carboalkoxyl group
  C) carbonyl group
  D) carboxyl group
  Show Answer
  The correct answer is D .
• Question 749:

  The two ions responsible for hardness in water are

  Options:
  A) Ca${}^{2+}$ and / or Mg${}^{2+}$
  B) K${}^{+}$ and / or Mg${}^{2+}$
  C) Ca${}^{2+}$ and / or Li${}^{+}$
  D) Ca${}^{2+}$ and / or Na${}^{+}$
  Show Answer
  The correct answer is A .
• Question 750: The decolourization of purple colour of tetraoxomanganate (VII) ion is a test for Options:
  A) alkenes
  B) alkanols
  C) alkanals
  D) alkanes
  Show Answer
  The correct answer is A .