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 1161: An anhydride is Options:
  A) a compound wich has no water of crystallization
  B) an oxide whose solution in water has a PH greater than 7
  C) an oxide whose solution in water has a PH less than 7
  D) an oxide that has hydrogen atoms
  E) an amphoteric oxide
  Show Answer
  The correct answer is C .
• Question 1162: The ores that can be concentrated by flotation are Options:
  A) nitride ores
  B) sulphide ores
  C) oxide ores
  D) non-metals
  Show Answer
  The correct answer is B .
• Question 1163:

  

  The IUPAC nomenclature for the compound above is

  Options:
  A) dimethlhexane
  B) 3,5 dimethylhexane
  C) 1.1 dmethyl, 3 methylpentane
  D) 2.4 dimethylhexane
  Show Answer
  The correct answer is D .
• Question 1164: 2.85g of an oxide of copper gave 2.52g of copper on reduction and 1.90g of another oxide gave 1.52g of copper on reduction. The data above illustrates the law of? Options:
  A) constant composition
  B) conservation of mass
  C) reciprocal proportions
  D) multiple proportions
  Show Answer
  The correct answer is D .
• Question 1165: A major source of oxide of oxygen is from the burning of Options:
  A) coal
  B) wood
  C) fuel
  D) chlorofluorocarbons
  Show Answer
  The correct answer is A .
• Question 1166:

  What type of reaction is involved in the formation of alkanols from alkenes?

  Options:
  A) Elimination reaction
  B) Redox reaction
  C) Substitution reaction
  D) Addition reaction
  Show Answer
  The correct answer is D .
• Question 1167:

  

  The above diagram gives the potential energy profile of the catalyst and uncatalysed reactions of X_(g) + Y_(g) → XY_(g). Deduce the respective activation energies in KJ of the catalysed and uncatalysed reverse reactions: XY(g) → X_(g) + Y_(g)

  Options:
  A) 300, 500
  B) 500, 300
  C) -300, -500
  D) -500, -300
  Show Answer
  The correct answer is A .
• Question 1168: When a piece of charcoal enclosed in a cylinder containing air is ignited Options:
  A) the toatl volume of air is increased
  B) the relative amount of oxygen present is increased
  C) the relative amount of nitrogen present is decreased
  D) the relative amount of carbondioxide present is increased
  E) the ratio of oxygen to nitrogen in the system is increased
  Show Answer
  The correct answer is D .
• Question 1169: Which of the following statements is INCORRECT?
  Options:
  A) Fractional distillation of crude petroleum will give the folloing hydrocarbon fuels in order of increasing boiling point
  B) Butane < petrol < kerosene of polythene.
  C) Both but-1-ene and but-1-yne will decolorize bromine readily
  D) but-2-ene will react with chlorine to form 2,3-dichlorobutane
  E) calcuim carbide will react with water to form any alkyne
  Show Answer
  The correct answer is E .
• Question 1170: Cotton is almost pure? Options:
  A) starch
  B) protein
  C) animal fibre
  D) celluose
  E) mineral fibre
  Show Answer
  The correct answer is D .