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 351:

  Wrought iron is obtained by heating cast iron in a furnace with?

  Options:
  A) magnetite
  B) haematite
  C) carbon(ii)oxide
  D) calcium trioxosilicate(iv)
  Show Answer
  The correct answer is B .
• Question 352:

  

  From the diagram above, an ideal can be represented by

  Options:
  A) M
  B) N
  C) K
  D) L
  Show Answer
  The correct answer is B .
• Question 353: Three liquids X, Y and Z containing only hydrogen and carbon were burnt on a spoon. X and Y burnt with sooty flames while Z did not. Y is able to discharge the colour of bromine water whereas X and Z cannot. Which of the liquids would be aromatic in nature? Options:
  A) X and Z
  B) Y
  C) X
  D) Z
  Show Answer
  The correct answer is B .
• Question 354: Trioxonitrate (V) acid is not used for preparing hydrogen gas from metals because it Options:
  A) is strongly oxidizing
  B) is volatile
  C) renders the metal passive
  D) forms a layer of oxide on the metal
  Show Answer
  The correct answer is A .
• Question 355: In the industrial production of H₂ is removed by (solution) Options:
  A) washing under pressure
  B) drying over phosphorus (V) oxide
  C) passing the mixture to the limewater
  D) using ammonical copper (I) chlorine
  Show Answer
  The correct answer is A .
• Question 356:

  CH_4(g) + Cl_2(g) → CH₃ Cl_(s) + HCl_(g)

  The major factor that influence the rate of the reaction above is

  Options:
  A) catalyst
  B) temperature
  C) concentration
  D) light
  Show Answer
  The correct answer is D .
• Question 357: When sodium nitrate dissolves in water, ∆H is positive. This means that? Options:
  A) the reaction is catalysed
  B) the reaction is complete
  C) the reaction is exothermic
  D) the reaction is endthermic
  E) sodium nitrate is highly soluble in water
  Show Answer
  The correct answer is D .
• Question 358: The process of converting starch to ethanol is Options:
  A) cracking
  B) distillation
  C) fermentation
  D) oxidation
  Show Answer
  The correct answer is C .
• Question 359: When a salt loses its water of crystallization to the atmosphere on exposure, the process is said to be Options:
  A) Efflorescence
  B) Deliquescence
  C) Effervescence
  D) Fluorescence
  Show Answer
  The correct answer is A .
• Question 360: Which of these metals, Mg, Fe, Pb and Cu will dissolve in dilute HCI? Options:
  A) All the metals
  B) Mg ,Fe and Cu
  C) Mg, Fe and Pb
  D) Mg and Fe only
  E) Mg only
  Show Answer
  The correct answer is D .