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 1821: Which of the following sulphides is insoluble in dilute HCl? Options:
  A) Na₂S
  B) ZnS
  C) CuS
  D) FeS
  Show Answer
  The correct answer is C .
• Question 1822: Due to the unstable nature of ethyne, it is stored by dissolving in Options:
  A) ethane-1,2-diol
  B) propanol
  C) ethanoic acid
  D) propanone
  Show Answer
  The correct answer is D .
• Question 1823: Terylene is synthesized from ethane- 1, 2-diol and benzene - 1, 4-dicarboxylic acid by? Options:
  A) addition reaction
  B) condensation reaction
  C) elimination reaction
  D) substitution reaction
  Show Answer
  The correct answer is B .
• Question 1824: X is a crystalline salt of sodium solution of X in water turns litmus red and produces a gas which turns lime water milky when added to sodium carbonate. With barium chloride solution, X gives hydrochloric acid. X is Options:
  A) Na ₂CO ₃
  B) NaHCO ₃
  C) NaHSO ₄
  D) Na ₂SO ₄
  Show Answer
  The correct answer is C .
• Question 1825: Phosphorus is stored under water to prevent it from Options:
  A) Dehydrating
  B) Becoming inert
  C) Smelling
  D) Catching fire
  Show Answer
  The correct answer is D .
• Question 1826: The industrial preparation of hydrogen gas from water gas is referred to as Options:
  A) Bosch process
  B) Contact process
  C) Haber process
  D) Bayer Process
  Show Answer
  The correct answer is A .
• Question 1827: If glucose is heated with concentration tetraoxosulphate (VI) acid, it will be dehydrated to Options:
  A) carbon
  B) carbon (IV) oxide
  C) ethene
  D) ethanol
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  The correct answer is A .
• Question 1828:

  

  In the graph above, the activation energy of the catalyzed reaction is

  Options:
  A) 100KJ
  B) 300KJ
  C) 250KJ
  D) 200KJ
  Show Answer
  The correct answer is A .
• Question 1829: In the chemical reaction A + B $\to$ C + D, more of D is formed? Options:
  A) if the concentrated of A is reduced
  B) if the concentrated of B is reduced
  C) if the concentrated of C is reduced
  D) if the concentration of C is increased
  E) if D is continuously removed from the reaction mixture
  Show Answer
  The correct answer is E .
• Question 1830:

  A certain hydrocarbon on complete combustion at s.t.p produced 89.6dm${}^3$ of CO${}_2$ and 54g of water. The hydrocarbon should be

  Options:
  A) C${}_6$H${}_6$
  B) C${}_4$H${}_{10}$
  C) C${}_5$H${}_{10}$
  D) C${}_4$H${}_6$
  Show Answer
  The correct answer is D .