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 311:

  Calculate the volume in cm³ of oxygen evolved as s.t.p. when a current of 5 A is passed through acidified water for 193s

  {F = 96500 Cmol^-1, Molar volume of a gas at s.t.p. = 22.4 dm³}

  Options:
  A) 224.000 dm³
  B) 0.056 dm³
  C) 0.224 dm³
  D) 56.000 dm³
  Show Answer
  The correct answer is B .
• Question 312: Methanoic acid mixes with water in all proportions and has about the same boiling point as water which of the following methods would you adopt to obtain pure water from a mixture of stand, water and methanoic acid? Options:
  A) fractional distillation
  B) filtration followed by distillation
  C) neutralization with sodium hydroxide followed by distillation
  D) esterification with ethanol followed by distillation
  E) neutralization with sodium hydroxide followed by filtration
  Show Answer
  The correct answer is B .
• Question 313:

  

  Use the graph above to answer this question.If the gas is cooled, at what temperature will it start to condense?

  Options:
  A) 125 ^oC
  B) 150^oC
  C) 175^oC
  D) 250^oC
  Show Answer
  The correct answer is B .
• Question 314:

  The IUPAC name of the compound CF${}_3$CHBrCl is

  Options:
  A) 2-chloro-2-bromo-1,1,1-trifluoroethane
  B) 2-bromo-2-chloro-1,1,1-trifluoroethane
  C) 1-bromo-1-chloro-2,2,2-trifluoroethane
  D) 1,1,1-trifluoro-2-bromo-2-chloroethane
  Show Answer
  The correct answer is B .
• Question 315:

  117.0g of sodium chloride was dissolved in the solubility in 1.0dm³ of distilled water at 25^oC. Determine the solubility in mol dm^-3 of sodium chloride at that temperature

  [Na = 23, Cl = 35.5]

  Options:
  A) 1.0
  B) 2.0
  C) 3.0
  D) 4.0
  Show Answer
  The correct answer is B .
• Question 316:

  8g CH₄ occupies 11.2 dm³ at s.t.p. What volume would 22 g of CH₃CH₃ occupy under the same condition?

  (C = 12, H = 1)

  Options:
  A) 3.7 dm³
  B) 11.2 dm³
  C) 22.4 dm³
  D) 33.6 dm³
  Show Answer
  The correct answer is B .
• Question 317:

  ²²⁶₈₈Ra → ^x₈₆Rn + α - particle

  What is the value of x in the nuclear reaction above?

  Options:
  A) 220
  B) 222
  C) 226
  D) 227
  Show Answer
  The correct answer is B .
• Question 318: Which of these statements is TRUE about carbon (IV) oxide? Options:
  A) it supports combustion
  B) It is strongly acidic in water
  C) It is very soluble in water
  D) It supports the buring of magnesium to produce magnesium oxide
  Show Answer
  The correct answer is C .
• Question 319:

  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 320: Phenolphthalein in acidic solution is Options:
  A) red
  B) orange
  C) colourless
  D) yellow
  Show Answer
  The correct answer is C .