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 711:

  Calculate the mass of chlorine gas which occupies a volume of 1.12dm³ at s.t.p

  [Cl = 35.5, molar volume of gas at s.t.p = 22.4 dm³

  Options:
  A) 15.50 g
  B) 7.10 g
  C) 3.55 g
  D) 1.80 g
  Show Answer
  The correct answer is C .
• Question 712: Aluminium is extracted commercially from its ore by? Options:
  A) heating aluminium oxide with coke in a furance
  B) the electrolysis of fused aluminium oxide in cryolite
  C) treating cryolite with sodium hydroxide solution under prressure
  D) heating sodium aluminium silicate to a high temperature
  Show Answer
  The correct answer is B .
• Question 713:

  C₃H₅ - COH₃ =CH₂

  The IUPAC nomenclature of the structure above is

  Options:
  A) 3-methybut-3-ene
  B) 2-methylbut-1-ene
  C) 2-ethylprop-1-ene
  D) 2-methylbut-2-ene
  Show Answer
  The correct answer is B .
• Question 714: N₂O_4(g) ↔ 2NO_2(g). Increase in total pressure of the equilibrium reaction above will Options:
  A) produce more of NO_2(g) in the mixture
  B) convert all of N₂O_4(g) to NO_2(g)
  C) have no effect on the concentrations of NO_2(g)and N₂O_4(g)
  D) produce more of N₂O_4(g) in the mixture
  Show Answer
  The correct answer is D .
• Question 715: Which of the following metals does NOT form a stable trioxocarbonate (IV)? Options:
  A) Fe
  B) Al
  C) Zn
  D) Pb
  E) none of the options is correct
  Show Answer
  The correct answer is E .
• Question 716: A burning candle produces water and Options:
  A) Carbon (II) oxide
  B) Carbon (IV) oxide
  C) Oxygen
  D) Hydrogen
  Show Answer
  The correct answer is B .
• Question 717: Which of the following is used in the manufacture of bleaching powder? Options:
  A) Sulphur dioxide
  B) Chlorine
  C) Hydrogen tetraoxosulphate (VI)
  D) Hydrogen sulphide
  E) Nitrogen dioxide
  Show Answer
  The correct answer is B .
• Question 718: The iron (III) oxide impurity in bauxite can be removed by? Options:
  A) Fractional crystallization in acid solution
  B) dissolution in sodium hydroxide and filtration
  C) extraction with concentrated ammonia and reprecipitation
  D) electroysis of molten mixture
  Show Answer
  The correct answer is B .
• Question 719: Synthetic rubber obtained by the polymerization of chlorobutadiene in the presence of sodium is called? Options:
  A) teflon
  B) isoprene
  C) polythene
  D) neoprene
  Show Answer
  The correct answer is D .
• Question 720: 50 cm³ of sulphur (IV) oxide, 800 cm³ of ammonia, 450 cm³ of hydrogen chloride, 1.0 cm³ of at 15°C. Which of the following is suitable for demonstrating the fountain experiment? Options:
  A) Sulphur (IV) oxide hydrogen chloride
  B) Carbon (IV) oxide and amonia
  C) Amonia and hydrogen chloride
  D) Carbon (IV) oxide and surphur (IV) oxide
  Show Answer
  The correct answer is C .