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 391:

  NH₃ + H₃O⁺

  → NH₄⁺ + H₂O. It may be deduced from the reaction above that?

  Options:
  A) a redox reaction has occurred
  B) H₃O⁺ acts as an oxidizing agent
  C) H₃O⁺ acts as an acid
  D) water acts as ab acid
  Show Answer
  The correct answer is C .
• Question 392:

  

  The IUPAC name for

  Options:
  A) 2-methylbut-3-ene
  B) 2-methylbut-4-ene
  C) 3-methylbut-2-ene
  D) 3-methylbut-1-ene
  E) 3-methylpent-1-ene
  Show Answer
  The correct answer is D .
• Question 393:

  For the reaction NH₄NO₂ $\to$ N₂ + 2H₂O, calculate the volume of nitrogen that would be produced at S. T. P from 320 g of the dioxonitrate(iii)salt. (Relative atomic masses: N = 14, O = 16, H = 1)

  Options:
  A) 2.24 dm ³
  B) 224 dm³
  C) 1.12 dm ³
  D) 112 dm ³
  E) 4.48 dm ³
  Show Answer
  The correct answer is D .
• Question 394: The basicity of CH₃COOH is Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is A .
• Question 395: Excess phosphorus was burnt in a gas jar and the residual gas passed successively over concentrated KOH solution and concentration H₂SO₄ before being collected in a flask. The gases collected are? Options:
  A) carbon (IV) oxide, nitrogen and the rare gases
  B) nitrogen and the rare gases
  C) carbon (IV) oxide, nitrogen (IV) oxide and the rare gases
  D) carbon (IV) oxide
  Show Answer
  The correct answer is C .
• Question 396: A compound gives an orange-red colour to non-luminous flame. This compound is likely to contain Options:
  A) Na⁺
  B) Ca²⁺
  C) Fe³⁺
  D) Fe²⁺
  Show Answer
  The correct answer is B .
• Question 397: Coffee stains can best be removed by Options:
  A) Kerosine
  B) turpentine
  C) a solution of borax in water
  D) ammonia solution
  Show Answer
  The correct answer is C .
• Question 398: The postulate of Dalton's atomic theory which still holds is that Options:
  A) atoms can neither be created nor destroyed
  B) the particles of the same element are exactly alike
  C) particles of different elements combine in simple whole number ratio
  D) all elemets are made of small indivisible particles
  Show Answer
  The correct answer is A .
• Question 399: A gas that is not associated with global warming is Options:
  A) CO₂
  B) SO₃
  C) CH₄
  D) H₂
  Show Answer
  The correct answer is A .
• Question 400: Which of the following metals will displace iron from a solution of iron(ll)tetraoxosulphate(lV)? Options:
  A) Copper
  B) Mercury
  C) Silver
  D) Zinc
  E) Gold
  Show Answer
  The correct answer is D .