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 1401:

  

  Which of the following compounds is a secondary alkanol?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is A .
• Question 1402: Which of the following statements is correct about the periodic table? Options:
  A) Elements in the same group have the same number of electron shells
  B) The non-metallic properties of the elements tend to decrease across each period
  C) Elements in the same period have the same number of valence electrons
  D) The valence electrons of the elements increase progressively across the period
  Show Answer
  The correct answer is D .
• Question 1403: Diamond cannot be used Options:
  A) In making bicycle chains
  B) As abrasives
  C) In cutting glass and metals
  D) As dies for drawing wires
  Show Answer
  The correct answer is A .
• Question 1404: Hardness of water is mainly due to the presence of Options:
  A) calcium hydroxide or magnesium hydroxide
  B) calcium trioxocarbonate (IV) or calcium tetraoxosulphate (VI)
  C) sodium hydroxide or magnesium ydroxide
  D) calcium chloride or sodium chloride salts
  Show Answer
  The correct answer is B .
• Question 1405:

  

  Z in diagram above represents

  Options:
  A) heat of reaction
  B) activation energy
  C) free energy
  D) entropy of reaction
  Show Answer
  The correct answer is A .
• Question 1406: the elements that belong to the third period of the periodic table are Options:
  A) Li, Be, Al and P
  B) Na, P, O and Cl
  C) B, C, N and O
  D) Nz, Mg, S and Ar
  Show Answer
  The correct answer is D .
• Question 1407: What is the oxidation number of Z in K₃ZCl₆? Options:
  A) -3
  B) +3
  C) -6
  D) +6
  Show Answer
  The correct answer is B .
• Question 1408: Which experiment led to the measurement of the charge on an electron? Options:
  A) Mass spectrometric experiment
  B) Oil-drop experiment
  C) Scattering α - particles
  D) Discharge-tube experiment
  Show Answer
  The correct answer is B .
• Question 1409: A cracking process in petroleum refining can be represented by Options:
  A) heptane to heptene
  B) heptane to 3-methylhexane
  C) heptane to propene and butane
  D) heptane to 2,3,3-trimethybutane
  Show Answer
  The correct answer is C .
• Question 1410: The structural component that makes detergent dissolve more quickly in water than soap is Options:
  A) -SO₃- Na⁺
  B) -COO-Na^-
  C) -SO₄- Na⁺
  D) -COO-K⁺
  Show Answer
  The correct answer is A .