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 511: CaO_s + H₂O_(l) → Ca(OH)_2(s) ΔH -65 kj. The process represented by the above equation is known as? Options:
  A) dissolution
  B) slaking
  C) liming
  D) mortaring
  Show Answer
  The correct answer is B .
• Question 512: What is the volume of oxygen required to bum completely 45cm${}^3$ of methane at s.t.p? Options:
  A) 135.0cm${}^3$
  B) 180.0cm${}^3$
  C) 45.0cm${}^3$
  D) 190.0cm${}^3$
  E) 90.0cm${}^3$
  Show Answer
  The correct answer is E .
• Question 513:

  At S. T. P how many litres of hydrogen can be obtained from the reaction of 500 cm³ of 0.5 M H ₂SO ₄ with excess zinc metal?

  (Gram molecular volume of H₂ = 22. 4 dm ³)

  Options:
  A) 22.4 dm ³
  B) 11 . 2 dm ³
  C) 6. 5 dm ³
  D) 5. 6 dm ³
  E) 0. 00 dm ³
  Show Answer
  The correct answer is D .
• Question 514: How many moles of oxygen molecules would be produced from the decomposition of 2.50 moles of potassium trioxochlorate (V)? Options:
  A) 2.50
  B) 3.50
  C) 3.75
  D) 7.50
  Show Answer
  The correct answer is C .
• Question 515:

  The heat required to raise the temperature of the body by 1k is called?

  Options:
  A) Specific heat
  B) Thermal capacity
  C) Water equivalent
  D) None of the above
  Show Answer
  The correct answer is B .
• Question 516: What reaction takes place when palm-oil is added to potash and foam are observed? Options:
  A) Neutralization
  B) Saponification
  C) Esterification
  D) Salting-out
  Show Answer
  The correct answer is B .
• Question 517: Ca(OH)_2(s) + 2NH₄Cl_(g) → CaCl_2(s) + 2H₂O_2(l) + X. In the reaction above X is Options:
  A) NO₂
  B) NH₃
  C) N₂O
  D) NO₂
  Show Answer
  The correct answer is B .
• Question 518: An example of a secondary amine is? Options:
  A) propylene
  B) di-butylamine
  C) methylamine
  D) trimethylamine
  Show Answer
  The correct answer is B .
• Question 519:

  A metal M displaces zinc from ZnCl, solution, solution

  This shows that

  Options:
  A) electrons flow from zinc to M
  B) M is more electropositive than zinc
  C) M is more electonegative than zinc
  D) zinc is more electropositive than M
  Show Answer
  The correct answer is B .
• Question 520:

  

  In the diagram, the function of the concentrated H₂SO₄ is to

  Options:
  A) purify the gas
  B) dry the gas
  C) liquefty the gas
  D) remove odour
  Show Answer
  The correct answer is B .