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 871: Which of the following compounds will burn with a brick-red colour in a non-luminous Bunsen flame? Options:
  A) LiCI
  B) NaCl
  C) CaCl₂
  D) MgCl₂
  Show Answer
  The correct answer is C .
• Question 872: The compound that is used as an anaesthetic is Options:
  A) CCl₄
  B) CH Cl₃
  C) CH₂Cl₂
  D) CH₃Cl
  Show Answer
  The correct answer is B .
• Question 873:

  

  The compound above is an

  Options:
  A) ether
  B) ester
  C) alkanal
  D) alkanol
  Show Answer
  The correct answer is B .
• Question 874:

  

  Carbon (ll) oxide may be collected as shown above because it

  Options:
  A) is heavier than air
  B) is less dense than air
  C) is insoluble in water
  D) burns in oxygen to form carbon (IV) oxide
  Show Answer
  The correct answer is C .
• Question 875:

  C_(s) + H₂O_(g) → H_2(g) + CO_2(g)

  ΔG for the reaction above at 1300k is -43KJ. At this temperature, the reaction is

  Options:
  A) not feasible
  B) at equilibrium
  C) feasible
  D) exothermic
  Show Answer
  The correct answer is C .
• Question 876: The characteristic colour of the flame shown when a copper sail moistened with concentrated hydrochloric acid on a platinum wire is put on bunsen burner is Options:
  A) lilac
  B) green
  C) yellow
  D) brick-red
  Show Answer
  The correct answer is B .
• Question 877: Chlorine is produced commercially by? Options:
  A) electrolysis of dilute hydrochloric acid
  B) electrolysis of brine
  C) neutralization of hydrogen chloride
  D) heating potassium trioxochlorate (V)
  Show Answer
  The correct answer is B .
• Question 878: Which of these properties gives a solid its definite shape? Options:
  A) strong intermolecular attraction
  B) high melting point
  C) high boiling point
  D) weak intermolecular attraction
  Show Answer
  The correct answer is A .
• Question 879: When each of the nitrates of Potassium, Magnesium and iron is heated, Options:
  A) all the nitrates decompose to their oxides
  B) the nitrate of magnesium gives the nitrite and oxygen
  C) the nitrates of iron magnesium and iron give the oxides
  D) the nitrate of iron gives the nitrite and oxygen
  E) the nitrate of the magnesium is not decomposed
  Show Answer
  The correct answer is C .
• Question 880:

  Chromatography is used to separate components of mixture which differ in their rates of ?

  Options:
  A) diffusion
  B) migration
  C) reaction
  D) sedimentation
  Show Answer
  The correct answer is B .