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 2011: Rare gases are suitable because they Options:
  A) are monoatomic
  B) form ions easily
  C) have duplet or octet electronic configuration in the outermost shells in their atoms
  D) are volatile gases
  Show Answer
  The correct answer is C .
• Question 2012:

  Crude petroleum is converted to useful products by the processof?

  Options:
  A) fractional crystallization
  B) fractional distillation
  C) filtration
  D) chromatography
  Show Answer
  The correct answer is B .
• Question 2013: If y is an oxidizing agent that reacts with a reducing agent, Z, which of the following is correct? Options:
  A) Y increases in oxidation number
  B) Y becomes reduced
  C) Z loses protons
  D) Z gains protons
  Show Answer
  The correct answer is B .
• Question 2014: The confirmatory test for alkanoic acids in organic qualitative analysis is the? Options:
  A) turning of wet blue litmus paper red
  B) reaction with alkanols to form esters
  C) reaction with sodium hydroxide to form salt and water
  D) reaction with aqueous Na₂COsp₃ to liberate a gas which turns lime water milky
  Show Answer
  The correct answer is B .
• Question 2015:

  2C₂H_2(g) + 5O_2(g) → 4CO_2(g) + 2H₂O_(g)

  In the reaction above, the mass of carbon(IV)oxide produced on burning 78 g of ethyne is

  [C =12, O = 16, H = 1]

  Options:
  A) 264 g
  B) 39 g
  C) 352 g
  D) 156 g
  Show Answer
  The correct answer is A .
• Question 2016:

  Which of the following metals cannot replace hydrogen from water or steam?

  Options:
  A) Sodium
  B) Magnesium
  C) Iron
  D) Calcium
  Show Answer
  The correct answer is D .
• Question 2017:

  SO${}_2$ + O${}_2$ 2SO${}_3$

  In the reaction above, the most suitable catalyst is?

  Options:
  A) chromium(vi)oxide
  B) iron(iii)oxide
  C) copper(i)oxide
  D) vanadium(v)oxide
  Show Answer
  The correct answer is D .
• Question 2018:

  Which of the following is the electronic configuration of sodium?

  (Atomic number of Na = 11)

  Options:
  A) 1s² 2s²2p⁶ 3s²
  B) 1s² 2s²2p⁶ 3s² 3p1s² 2s²2p⁶ 3s¹
  C) 1s² 2s²2p⁶ 3s¹
  D) 1s² 2s²2p⁶ 3s^°
  E) 1s² 2s²2p⁶ 4s¹
  Show Answer
  The correct answer is C .
• Question 2019:

  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 2020:

  A compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen. If the molar mass of the compound is 180. Find the molecular formula.

  [H = 1, C = 12, O = 16]

  Options:
  A) C${}_3$H${}_6$O${}_3$
  B) C${}_6$H${}_6$O${}_3$
  C) C${}_6$H${}_{12}$O${}_6$
  D) CH${}_2$O
  Show Answer
  The correct answer is C .