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 61:

  

  The elections or two atoms Y and Z are arranged in shes as shown above. The bond formed between the atoms of Y and Z is

  Options:
  A) ionic
  B) convalent
  C) dative
  D) metallic
  Show Answer
  The correct answer is B .
• Question 62: The oxidation number of manganese in KMnO₄ is? Options:
  A) +1
  B) +3
  C) +5
  D) +7
  E) +2
  Show Answer
  The correct answer is D .
• Question 63:

  NO_(g) + CO_(g) ↔ (1)/(2)N_2(g) + CO_2(g) ∆H = -89.3 kj.

  What conditions would favour maximum conversion of nitrogen (II) oxide and carbon (II) oxide in the reaction above?

  Options:
  A) Low temperature and high pressure
  B) High temperature and low pressure
  C) High temperature and high pressure
  D) Low temperature and low pressure
  Show Answer
  The correct answer is A .
• Question 64:

  Alkanol + Alkanoic ↔ Ester + Water

  The reverse reaction above is known as

  Options:
  A) Hydrolysis
  B) Saponification
  C) Hydration
  D) Fermentation
  Show Answer
  The correct answer is A .
• Question 65:

  An electron can be added to a halogen atom to form a halide ion with?

  Options:
  A) 8 valence electrons
  B) 7 valence electrons
  C) 2 valence electrons
  D) 3 valence electrons
  Show Answer
  The correct answer is A .
• Question 66:

  An element, X, forms a volatile hydride XH₃ with a vapour density of 17.0. The relative atomic mass of X is?

  (H = 1)

  Options:
  A) 34.0
  B) 31.0
  C) 20.0
  D) 14.0
  Show Answer
  The correct answer is B .
• Question 67:

  

  Which of the gas laws does the above graph illustrate?

  Options:
  A) Boyle
  B) Charles
  C) Graham
  D) Gay-Lussac
  Show Answer
  The correct answer is B .
• Question 68:

  

  Use the option above to answer this question. Which is the correct set of results for tests conducted respectively on fresh lime juice and ethanol.

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is A .
• Question 69: The principal constituent of natural gas is Options:
  A) methane
  B) ethane
  C) propane
  D) Butane
  Show Answer
  The correct answer is A .
• Question 70: In dilute solution the heat of the reaction NaOH + HCl = NaCl + H2O is - 57.3kJ. Therefore the heat of the reaction 2NaOH + H₂SO₄ $\to$ Na₂SO₄ + 2H₂O is Options:
  A) + 28.65 kJ
  B) - 28.65KJ
  C) + 57.3KJ
  D) - 114.6 KJ
  E) - 229.2 KJ
  Show Answer
  The correct answer is D .