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 1201:

  H${}^{+}$ + OH${}^{-}$ H${}_2$O

  The equation above illustrates

  Options:
  A) precipitation
  B) hydration
  C) hydrolysis
  D) neutralization
  Show Answer
  The correct answer is D .
• Question 1202: Which of the following methods can be used to obtain pure water from a mixture of sand, water and methanoic acid? Options:
  A) netralization with NaOHfoolowed by filtration
  B) neutralization with NaOH followed by distillation
  C) fractional distillation
  D) filtration followed by distillation
  Show Answer
  The correct answer is D .
• Question 1203:

  Which of the following is an example of a primary cell?

  Options:
  A) Alkaline battery
  B) Nickel-cadmium battery
  C) Lead-acid battery
  D) Lithium-ion battery
  Show Answer
  The correct answer is A .
• Question 1204: A change in the temperature of a saturated solution disturbs the equilibrium between the Options:
  A) Undissolved solute and the solvent
  B) Dissolved solute and the solvent
  C) Dissolved solute and the undissolved solute
  D) Dissolved solute and the solution
  Show Answer
  The correct answer is C .
• Question 1205: A given mass of gas occupies 2dm³ at 300k. At what temperature will its volume be doubled, keeping the pressure constant? Options:
  A) 400k
  B) 480k
  C) 550k
  D) 600k
  Show Answer
  The correct answer is D .
• Question 1206: Water is said to be temporarily hard when it contains Options:
  A) Ca (HCO₃)₂ and Mg (HCO₃)₂ salts
  B) Ca (HCO₃)₂ and CaCO₃ SALTS
  C) Mg(HCO₃)₂ and CaSO₄ salts
  D) CaSO₄ and Ca(HCO₃)₂ salts
  Show Answer
  The correct answer is A .
• Question 1207: The set of pollutants that is most likely to be produced when petrol is accidentally spilled on plastic materials and ignited is Options:
  A) CO, CO² and SO²
  B) CO, HCL and SO²
  C) CO, CO² and HCL
  D) SO², CO² and HCL
  Show Answer
  The correct answer is B .
• Question 1208: Ethene reacts with hydrogen bromide to give Options:
  A) CH₂Br₂
  B) CH₃CH₂Br
  C) C₂H₂Br₂
  D) CHBr₂
  Show Answer
  The correct answer is B .
• Question 1209: The compound produced when sodium peroxide is heated with excess sodium is Options:
  A) Na₂CO₃
  B) Na₂O
  C) NaNO₂
  D) NaOH
  Show Answer
  The correct answer is B .
• Question 1210: A gas X diffuses twice as fast as gas Y. if the relative molecular mass of X is 32, calculate the relative molecular mass of Y. Options:
  A) 128
  B) 8
  C) 16
  D) 64
  Show Answer
  The correct answer is A .