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 841: The simplest branched-chain hydrocarbon is Options:
  A) ethane
  B) ethene
  C) propane
  D) butane
  Show Answer
  The correct answer is D .
• Question 842:

  How many bonding pair are present in carbon(iv)oxide?

  Options:
  A) 4
  B) 3
  C) 2
  D) 1
  Show Answer
  The correct answer is A .
• Question 843: When a salt loses its water of crystallization to the atmosphere on exposure, the process is said to be Options:
  A) Efflorescence
  B) Deliquescence
  C) Effervescence
  D) Fluorescence
  Show Answer
  The correct answer is A .
• Question 844: A few drops of NaOH solution was added to an unknown salt forming a white precipitate which is insoluble in excess solution. The cation likely present is Options:
  A) Zn²⁺
  B) Pb²⁺
  C) Ca²⁺
  D) Al³⁺
  Show Answer
  The correct answer is C .
• Question 845: Which of the following CANNOT be obtained by fractional distillation of petroleum? Options:
  A) Ether
  B) Methane
  C) Butane
  D) Ethene
  E) Hydrogen
  Show Answer
  The correct answer is E .
• Question 846: How many moles of (H+) are there in 1 dm³ of 0.5 M solution of H₂SO₄? Options:
  A) 2.0 moles
  B) 1.0 moles
  C) 0.5 mole
  D) 0.25 mole
  Show Answer
  The correct answer is B .
• Question 847:

  What volume of oxygen is produced from the decomposition of 2 mole of KCIO₃ at s.t.p?

  [Molar volume of a gas at s.t.p = 22.4 dm³]

  Options:
  A) 22.4 dm³
  B) 33.6 dm³
  C) 44.8 dm³
  D) 67.2 dm³
  Show Answer
  The correct answer is D .
• Question 848:

  

  How many more isomers of the compound above can be obtained ?

  Options:
  A) 5
  B) 4
  C) 3
  D) 2
  Show Answer
  The correct answer is B .
• Question 849:

  An organic compound which liberate carbon(iv)oxide from trioxocarbonate(iv) solution is likely to be?

  Options:
  A) C${}_2$H${}_5$OH
  B) C${}_3$H${}_4$
  C) C${}_6$H${}_6$
  D) CH${}_3$COOH
  Show Answer
  The correct answer is D .
• Question 850:

  How many grams of methylacetylene (propyne) CH₃ - C Ξ CH will completely discharge the colour of 8g of bromine?

  (Br = 80, C = 12, H = 1)

  Options:
  A) 0.5
  B) 1.0
  C) 2.0
  D) 3.0
  E) 4.0
  Show Answer
  The correct answer is B .