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 331: The condition required for corrosion to take place is the presence of Options:
  A) water and carbon (IV) oxide
  B) water, carbon (IV) oxide and oxygen
  C) oxygen and carbon (IV) oxide
  D) water and oxygen
  Show Answer
  The correct answer is D .
• Question 332: 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 333: Which of these statements is TRUE about carbon (IV) oxide? Options:
  A) it supports combustion
  B) It is strongly acidic in water
  C) It is very soluble in water
  D) It supports the buring of magnesium to produce magnesium oxide
  Show Answer
  The correct answer is C .
• Question 334:

  An organic compound which liberate carbon(iv)oxide from trioxocarbonate(iv) solution is likely to be?

  Options:
  A) C${}_2$H${}_5$OH
  B) C${}_3$H${}_4$
  C) C${}_6$H${}_6$
  D) CH${}_3$COOH
  Show Answer
  The correct answer is D .
• Question 335: The modern process of manufacturing steel for iron is by Options:
  A) treatment with acids
  B) oxidation
  C) blast reduction
  D) treatment with alkanal
  Show Answer
  The correct answer is C .
• Question 336:

  A solution X, on mixing with AgNO${}_3$ solution gives a white precipitate soluble in aqueous NH${}_3$, a solution Y, when also added to X, also gives a white precipitate which is soluble when heated solutions X and Y respectively contain

  Options:
  A) Al${}^{3+}$, Cl${}^{-}$
  B) Hg${}^{+}$, SO${}_4^{2-}$
  C) Pb${}^{2+}$, Cl${}^{-}$
  D) Ag${}^{+}$, SO${}_4^{2-}$
  Show Answer
  The correct answer is C .
• Question 337:

  The cost of discharging 6.0g of a divalent metal, X from its salt is ₦12.00. What is the cost of discharging 9.0g of a trivalent metal, Y from its salt under the same condition?

  [X = 63, Y = 27, 1F = 96,500C]

  Options:
  A) N12.00
  B) N27.00
  C) N63.00
  D) N95.00
  Show Answer
  The correct answer is C .
• Question 338: Environmental pollution is worsened by the release from automobile exhausts of Options:
  A) Water vapour
  B) Steam
  C) Smoke
  D) Heavy metals
  Show Answer
  The correct answer is C .
• Question 339: Which of the following statements is true? When the potassium atom forms its ion Options:
  A) it gains one electron and becomes neutral
  B) its atomic number decreases
  C) it achieves electronic configuration of orgon
  D) it loses one proton
  E) it loses one neutron
  Show Answer
  The correct answer is C .
• Question 340: How many hydrogen atoms does a single ring cycloalkane have less than the corresponding open-chain alkane? Options:
  A) Two
  B) Three
  C) Four
  D) One
  Show Answer
  The correct answer is A .