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 591:

  Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore,

  Options:
  A) P will form an electrovalent bond with R
  B) Q will form a covalent bond with S
  C) R will form an electrovalent bond with S
  D) Q will form an electrovalent bond with S
  E) Q will form a covalent bond with R
  Show Answer
  The correct answer is D .
• Question 592:

  When the end alkyl groups of ethyl ethanoate are interchanged, the compound formed is

  Options:
  A) propylmethanoate
  B) ethylpropanoate
  C) methyl ethanoate
  D) methyl propanoate
  Show Answer
  The correct answer is B .
• Question 593:

  

  The diagram above represents an atom of

  Options:
  A) magnesium
  B) helium
  C) chlorine
  D) neon
  Show Answer
  The correct answer is A .
• Question 594: A particle that contains 11 protons, 12 neutrons and 10 electrons is probably a Options:
  A) neutral non-metal
  B) metallic ion
  C) non-metallic ion
  D) neutral metal
  Show Answer
  The correct answer is B .
• Question 595: When steam is passed over red-hot carbon, the substances produced are Options:
  A) Hydrogen and trioxocarbonate (IV) acid
  B) Hydrogen, oxygen and carbon (IV) oxide
  C) Hydrogen and carbon (II) oxide
  D) Hydrogen and carbon (IV) oxide
  Show Answer
  The correct answer is C .
• Question 596:

  

  The IUPAC name for

  Options:
  A) 2-methylbut-3-ene
  B) 2-methylbut-4-ene
  C) 3-methylbut-2-ene
  D) 3-methylbut-1-ene
  E) 3-methylpent-1-ene
  Show Answer
  The correct answer is D .
• Question 597:

  A given volume of methane diffuses in 20s. How long will it take the same volume of sulphur (IV) oxide to diffuse under the same conditions?

  [C = 12, H = 1, S = 32, O = 16].

  Options:
  A) 5s
  B) 20s
  C) 40s
  D) 60s
  Show Answer
  The correct answer is C .
• Question 598:

  ZnO_(s) + CO_(g) → Zn_(s) + CO_2(g)

  In the reaction above, Zinc has been

  Options:
  A) decomposed
  B) displaced
  C) oxidized
  D) reduced
  Show Answer
  The correct answer is D .
• Question 599: Elements X and Y have electronic configurations 1s²2s²2p⁶ and 1s²2s²2p⁶3s²3p¹ respectively. When they combine, the formula of the compound formed is Options:
  A) XY
  B) YX
  C) X₂Y₃
  D) Y₂X₃
  Show Answer
  The correct answer is D .
• Question 600:

  Which of the following pairs of substances will react further with oxygen to form a higher oxide?

  Options:
  A) CO${}_2$ and H${}_2$O
  B) NO and H${}_2$O
  C) CO and CO${}_2$
  D) SO${}_2$ and NO
  Show Answer
  The correct answer is D .