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 1111: MnO^-₄ + 8H⁺ + ne → Mn⁺⁺ + 4H₂O. Which is the value of n in the reaction above? Options:
  A) 2
  B) 3
  C) 4
  D) 5
  Show Answer
  The correct answer is D .
• Question 1112: Hydrogen diffuses through a porous plug Options:
  A) at the same rate as oxygen
  B) at a slower rate than oxygen
  C) twice as fast as oxygen
  D) three times as fast as oxygen
  E) four times as fast as oxygen
  Show Answer
  The correct answer is E .
• Question 1113:

  CH₃ - CH₂ - C CH

  The hybridization in the compound above is

  Options:
  A) Sp²
  B) sp
  C) sp³ and sp²
  D) sp³ and sp
  Show Answer
  The correct answer is D .
• Question 1114:

  Zn_(s) + CuSO_4(aq) $\to$ ZnSO_4(aq) + Cu_(s)

  In the reaction above, the oxidizing agent is

  Options:
  A) CuSO_4(aq)
  B) ZnSO_4(aq)
  C) Cu_(s)
  D) Zn_(s)
  Show Answer
  The correct answer is A .
• Question 1115: A mixture of sand, ammonium chloride and sodium chloride is best separated by? Options:
  A) sublimation followed by addition of water and filteration
  B) sublimation followed by addition of water and evaporation
  C) addition of water followed by filtration and sublimation
  D) addition of water followed by crystallization and sublimation
  Show Answer
  The correct answer is A .
• Question 1116:

  What is the empirical formula of a compound containing 40.00% carbon, 6.67% hydrogen, and 53.33% oxygen by mass?

  Options:
  A) C${}_4$H${}_8$O${}_4$
  B) CH${}_2$O
  C) C${}_2$H${}_4$O${}_2$
  D) C${}_3$H${}_6$O${}_3$
  Show Answer
  The correct answer is B .
• Question 1117: Fe₂O_3(s) + 2Al_(s) → Al₂O₃ + 2Fe_(s) If the heats of formation of Al₂O₃ and Fe₂O₃ are - 1670 kj mol^-1 and - 822 kj mol^-1 respectively, the enthalpy change in kj for the reaction is ? Options:
  A) +2492
  B) +848
  C) -848
  D) -2492
  Show Answer
  The correct answer is C .
• Question 1118: Which of the following raw materials would be required from the smelting of iron ore in a blast furnace? Options:
  A) CaCO ₃
  B) Zn(NO₃)₂
  C) CuSO₄
  D) AICI₃
  E) CaSO₄
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  The correct answer is A .
• Question 1119: Which of the following is formed when maltose reacts with concentrated tetraoxosulphate (VI) acid ? Options:
  A) Carbon (IV) oxide
  B) Coal tar
  C) Charcoal
  D) Toxic fumes
  Show Answer
  The correct answer is C .
• Question 1120: The processes which return carbon (IV) oxide to the atmosphere include Options:
  A) respiration, decay and combustion
  B) photosynthesis, respiration and transpiration
  C) ozone depletion, combustion and decay
  D) photosynthesis, decay and respiration
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  The correct answer is A .