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: The alkaline hydrolysis of fats and oils produces soap and Options:
  A) propane 1, 1, 3 - triol
  B) propane - 1,2,3 - triol
  C) propane - 1,3,3 - triol
  D) propane - 1, 2, 2 - triol
  Show Answer
  The correct answer is B .
• Question 312: A little quantity of trichloromethane (b.pt 60,^oC) was added to a large quantity of ethanol (b.pt 78,^oC). The most probable boiling point of the resultant mixture is from Options:
  A) 69 ^oC - 70 ^oC
  B) 70 ^oC – 74 ^oC
  C) 82 ^oC – 84 ^oC
  D) 60 ^oC – 78 ^oC
  Show Answer
  The correct answer is C .
• Question 313:

  Given that 15.00 cm³ of H₂

  SO₄ was required to completely neutralize 25.00 cm³ of 0.125 mol dm^-3 NaOH, calculate the molar concentration of the acid solution:

  Options:
  A) 0.925 mol dm^-3
  B) 0.156mol dm^-3
  C) 0.104 mol dm^-3
  D) 0.023 mol dm^-3
  Show Answer
  The correct answer is C .
• Question 314: The pressure of 100cm³ of oxygen at 35^oC is 750mmHg. What will be the volume of gas if the pressure is reduced to 100mmHg without changing the temperature? Options:
  A) 650 cm³
  B) 850 cm³
  C) 580 cm³
  D) 750 cm³
  Show Answer
  The correct answer is D .
• Question 315:

  Methane is prepared in the laboratory by heating a mixture of sodium ethanoate with soda lime. The chemical constituent(s) of soda lime is/are

  Options:
  A) Ca(OH)${}_2$ and NaOH
  B) Na${}_2$CO${}_3$
  C) NaCl
  D) NaOH
  Show Answer
  The correct answer is A .
• Question 316: An element used in the production of matches is Options:
  A) nitrogen
  B) aluminium
  C) copper
  D) sulphur
  Show Answer
  The correct answer is D .
• Question 317: 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 318: On recrystallization, 20g of magnesium tetraoxosuphate (IV) forms 41 g of magnesium tetraoxosulphate (IV) crystals, MgSO₄. yH₂O. The value of y is?(Mg = 24, S = 32, O = 16, H = 1) Options:
  A) 1
  B) 3
  C) 5
  D) 7
  Show Answer
  The correct answer is D .
• Question 319:

  ¹⁴₆C → X + B

  X in the equation above represents

  Options:
  A) ¹²₆C
  B) ¹²₅B
  C) ¹⁴₇N
  D) ¹³₆C
  Show Answer
  The correct answer is C .
• Question 320:

  Chlorine gas is commonly used in the production of which of the following industrial compounds?

  Options:
  A) Chlorofluorocarbons (CFCs)
  B) Methane
  C) Ammonia
  D) Ethanol
  Show Answer
  The correct answer is A .