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 751:

  

  Which of the curves in the above graph illustrates the behaviour of an ideal gas?

  Options:
  A) W
  B) X
  C) Y
  D) Z
  Show Answer
  The correct answer is C .
• Question 752: When air is passed through alkaline pyrogallol and then over quicklime, the only gases left are? Options:
  A) nitrogen and carbondoxide
  B) the rare gases
  C) nitrogen and oxygen
  D) nitrogen and the rare gases
  E) nitrogen, carbonioxide and the rare gases
  Show Answer
  The correct answer is D .
• Question 753: Under high pressure, real gases do not obey gas laws because their molecules? Options:
  A) have become more energetic
  B) have become less energetic
  C) have become smaller in size
  D) decompose into atoms
  E) start repelling each other
  Show Answer
  The correct answer is B .
• Question 754:

  What quantity of electricity will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution?

  [ F = 96 5000 C mol^-1 ]

  Options:
  A) 24 125 coulombs
  B) 48 250 coulombs
  C) 72 375 coulombs
  D) 96 500 coulombs
  Show Answer
  The correct answer is B .
• Question 755: The ability of ionic solids is generally due to the? Options:
  A) negative electron affinity of most atoms
  B) crystal lattice forces
  C) electron pair sharing
  D) positive ionization potentials
  Show Answer
  The correct answer is B .
• Question 756:

  117.0g of sodium chloride was dissolved in the solubility in 1.0dm³ of distilled water at 25^oC. Determine the solubility in mol dm^-3 of sodium chloride at that temperature

  [Na = 23, Cl = 35.5]

  Options:
  A) 1.0
  B) 2.0
  C) 3.0
  D) 4.0
  Show Answer
  The correct answer is B .
• Question 757: Two gas cylinders contain ethylene (ethene) and acetylene respectively. One test which can be used to distinguish between them is by Options:
  A) passing each gas through bromine water
  B) passing each gas through dilute potassium permanganate solution
  C) passing each gas through silver nitrate solution
  D) treating each gas catalytically with excess hydrogen gas
  Show Answer
  The correct answer is C .
• Question 758: When sulphur (IV) oxide is passed into a solution of sodium hydroxide for a long time, it eventually produces a solution of Options:
  A) NaHSO₄
  B) Na₂SO₃
  C) NaHSO₃
  D) Na₂SO₄
  Show Answer
  The correct answer is B .
• Question 759: the minimum amount of energy required for a reaction to take place is Options:
  A) lattice energy
  B) ionization energy
  C) activation energy
  D) kinetic energy
  Show Answer
  The correct answer is C .
• Question 760:

  Which of the following pairs cannot be represented with a chemical formula?

  Options:
  A) air and bronze
  B) bronze and sodium chloride
  C) copper and sodium chloride
  D) caustic soda and washing soda
  Show Answer
  The correct answer is A .