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 251: Which of the following equilibria is shifted to the right as a result of an increase in pressure? Options:
  A) H_2(g) + I_2(g) 2HI_(g)
  B) 2NO_2(g) N₂O_4(g)
  C) PCl_5(s) PCl_3(s) + Cl_2(g)
  D) 2O_3(g) 3O_2(g)
  Show Answer
  The correct answer is B .
• Question 252: Environmental pollution is worsened by the release from the automobile exhaust of Options:
  A) water vapour
  B) steam
  C) smoke
  D) heavy metals
  E) steam and smoke
  Show Answer
  The correct answer is D .
• Question 253:

  The emission of two successive beta particles from the nucleus ${}_{15}^{32}P$ will produce

  Options:
  A) ${}_{14}^{30}$Si
  B) ${}_{13}^{32}$Al
  C) ${}_{17}^{32}$Cl
  D) ${}_{16}^{32}$S
  Show Answer
  The correct answer is C .
• Question 254:

  A given amount of gas occupies 10.0dm5 at 4atm and 273°C. The number of moles of the gas present is [Molar volume of gas at s.t.p = 22.4dm${}^3$]

  Options:
  A) 0.89 mol
  B) 1.90 mol
  C) 3.80 mol
  D) 5.70 mol
  Show Answer
  The correct answer is A .
• Question 255: 2- methylbutan- 2ol is an example of a Options:
  A) dihydric alkanol
  B) tertiary alkanol
  C) secondary alkanol
  D) primary alkanol
  Show Answer
  The correct answer is B .
• Question 256: According to Charle's law, the volume of a gas becomes zero at Options:
  A) −100°c
  B) −273°c
  C) −373°c
  D) 0°c
  Show Answer
  The correct answer is B .
• Question 257: The intermediate product formed when ethanol is progressively oxidized to ethanoic acid with potassium heptaoxodichromate (IV) is Options:
  A) butanal
  B) ethanal
  C) methanal
  D) propanal
  Show Answer
  The correct answer is B .
• Question 258:

  The process by which salt and water reacted in a limited way to form an acid or abase is?

  Options:
  A) Neutral process
  B) Basic acidic process
  C) Hydrolysis
  D) Sublimation
  Show Answer
  The correct answer is C .
• Question 259:

  What mass of magnesium would be obtained by passing a current of 2 amperes for 2 hours, through molten magnesium chloride?
  [1 faraday = 96500C, Mg = 24]

  Options:
  A) 1.12g
  B) 4.48g
  C) 1.80g
  D) 2.00g
  Show Answer
  The correct answer is C .
• Question 260: In the industrial production of H₂ is removed by (solution) Options:
  A) washing under pressure
  B) drying over phosphorus (V) oxide
  C) passing the mixture to the limewater
  D) using ammonical copper (I) chlorine
  Show Answer
  The correct answer is A .