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 421: When sodium ethanoate is treated with a few drops of concentrated tetraoxosulphate(vi)acid. one of the products is Options:
  A) CH₃COOH
  B) CH₃COOCH₃
  C) CH₃COOC₂H₅
  D) C₂H₅COOCH₃
  Show Answer
  The correct answer is A .
• Question 422: A side effect of soft water is that Options:
  A) it gives offensive taste
  B) excess calcium is precipitated
  C) it attacks lead contained in pipes
  D) it encourage the growth of bacteria
  Show Answer
  The correct answer is C .
• Question 423: 2 - methyl propan -2- ol is an example of a Options:
  A) primary alkanol
  B) secondary alkanol
  C) tertiary alkanol
  D) quartenary alkanol
  Show Answer
  The correct answer is C .
• Question 424: In a flame test for calcium, the flame appears Options:
  A) green when viewed through a blue glass
  B) blue when viewed through a blue glass
  C) orange -red when viewed through a blue glass
  D) brick-red when viewed through a blue-glass
  Show Answer
  The correct answer is D .
• Question 425: Which of the following compounds can be represented by the molecular formula C₂H₆O? Options:
  A) Propanel
  B) Ethanol
  C) Methanoic acid
  D) Glucose
  Show Answer
  The correct answer is B .
• Question 426: The industrial preparation of hydrogen gas from water gas is referred to as Options:
  A) Bosch process
  B) Contact process
  C) Haber process
  D) Bayer Process
  Show Answer
  The correct answer is A .
• Question 427: The order in which a mixture of sand, ammonium chloride and sodium chloride can be separated is Options:
  A) dissolution → dryness → filtration → evaporation
  B) filtration → sublimation → evaporation → dryness
  C) sublimation → dissolution → filtration → evaporation
  D) dissolution → filtration → sublimation → evaporation
  Show Answer
  The correct answer is C .
• Question 428: Which of the following pair of gases will NOT react further with oxygen at a temperature between 30^oC AND 400^oC Options:
  A) SO₂ and NH₃
  B) CO₂ and H₂
  C) NO₂ and SO₃
  D) SO₃ and NO
  E) CO and H₂
  Show Answer
  The correct answer is C .
• Question 429: An organic compound reacted with bromine water to give a colourless solution. The compound is probably an Options:
  A) alkene
  B) alkanal
  C) alkyne
  D) alkanone
  Show Answer
  The correct answer is C .
• Question 430: Which of the following equimolar solutions will have the highest pH? Options:
  A) CH₃COOHa
  B) NaOH
  C) HCl
  D) NH₄OH
  Show Answer
  The correct answer is B .