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 801: A solid X when heated gives off a brown gas. If X is soluble in excess sodium hydroxide solution but insoluble in excess ammonium hydroxide solution, then X is Options:
  A) basic lead carbonate
  B) lead (II) nitrate
  C) sodium carbonate
  D) zinc nitrate
  E) sodium nitrate
  Show Answer
  The correct answer is B .
• Question 802: P1V1 = P2V2 supports ? Options:
  A) Charles’s law
  B) Boyles’s law
  C) Graham’s law
  D) Avogadro’s law
  Show Answer
  The correct answer is B .
• Question 803: 30 cm³ of 0.1 M Al (NO₃)₃ SOLUTION IS RECTED WITH 100cm³ of 0.15M of NaOH solution. Which reactant is in excess, and by now much ? Options:
  A) NaOH solution by 70 cm³
  B) NaOH solution, by 60 cm³
  C) NaOH solution by 40 cm³
  D) Al(NO₃)₃ solution by 20 cm³
  E) Al(NO₃)₃ solution by 10 cm³
  Show Answer
  The correct answer is C .
• Question 804:

  An example of a polysaccharide is?

  Options:
  A) Dextrose
  B) Mannose
  C) Glucose
  D) Starch
  Show Answer
  The correct answer is D .
• Question 805: 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 806: In an attempt to remove sugar from a breaker containing a quantity of sand and sugar, 2 M ammonium chloride solution was accidentally added instead of water. Which of the following method could be used to remove the ammonium chloride from the mixture? Options:
  A) Fractional distillation
  B) crystallization
  C) Filtration followed by evaporation
  D) Evaporation followed by sublimation
  E) Filtration followed by sublimation
  Show Answer
  The correct answer is D .
• Question 807:

  An organic compound which decolorizes bromine water is likely to be?

  Options:
  A) C${}_3$H${}_8$
  B) C${}_2$H${}_6$
  C) C${}_4$H${}_{1}0$
  D) C${}_2$H${}_4$
  Show Answer
  The correct answer is D .
• Question 808: Which of the following represents the type of bonding present in ammonium chloride molecule? Options:
  A) Ionic only
  B) Covalent only
  C) Ionic and dative covalent
  D) Dative covalent only
  Show Answer
  The correct answer is C .
• Question 809:

  

  In the diagram above, mixture Y is

  Options:
  A) NH₄NO_3(s) + CaSO_4(s),/sub>
  B) NH₄CL_(s) + NaNO_2(s)
  C) NH₄NO_2(s) + Na₂SO_4(s)
  D) NH₄CL_(s) + Ca(OH)_2(s)
  Show Answer
  The correct answer is D .
• Question 810: When excess ethanol is heated to 145 ^oC in the presence of concentrated sulphuric acid, the product is Options:
  A) diethyl ether
  B) ethyne
  C) diethyl sulphate
  D) acetone
  E) ethanoic acid
  Show Answer
  The correct answer is A .