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 431: The compound that is used as an anaesthetic is Options:
  A) CCl₄
  B) CH Cl₃
  C) CH₂Cl₂
  D) CH₃Cl
  Show Answer
  The correct answer is B .
• Question 432: The acid in electrolysis of water is dilute Options:
  A) HNO₃
  B) CH₃COOH
  C) H₂SO
  D) HCl
  Show Answer
  The correct answer is C .
• Question 433: When excess ethanol is heated to 145 ^oC in the presence of concentrated sulphuric acid, the product is Options:
  A) diethyl ether
  B) ethyne
  C) diethyl sulphate
  D) acetone
  E) ethanoic acid
  Show Answer
  The correct answer is A .
• Question 434: Copper metal dissolves in concentrated trioxonitrate (V) acid with the resultant evolution of Options:
  A) CO₂
  B) SO₂
  C) NO₂
  D) CO
  Show Answer
  The correct answer is C .
• Question 435:

  Which of the following statements is true regarding the melting and boiling points of pure substances?

  Options:
  A) The boiling point is always higher than the melting point
  B) The melting point is always higher than the boiling point
  C) The melting and boiling points are always the same for all substances
  D) The melting and boiling points can vary depending on the substance
  Show Answer
  The correct answer is D .
• Question 436: The set of pollutants that is most likely to be produced when petrol is accidentally spilled on plastic materials and ignited is Options:
  A) CO, CO² and SO²
  B) CO, HCL and SO²
  C) CO, CO² and HCL
  D) SO², CO² and HCL
  Show Answer
  The correct answer is B .
• Question 437:

  

  From the diagram above, find the amount of solute deposited when 200 cm³ of the solution is cooled from 55^oC to 40^oC

  Options:
  A) 0.10 mole
  B) 0.20mole
  C) 0.01 mole
  D) 0.02 mole
  Show Answer
  The correct answer is B .
• Question 438: The major and most effective way of controlling pollution is to Options:
  A) improve machinery so that the substances released from combustion are less harmful
  B) pass strict laws against it by individuals and companies
  C) educate people on the causes and effects of pollution
  D) convert chemical wastes to harmless substances before releasing them into the environment
  Show Answer
  The correct answer is C .
• Question 439: Which of the following represents an aromatic compound? Options:
  A) C₆H₅OH
  B) C₆H₁₂
  C) C₆H₉OH
  D) C₆H₈
  Show Answer
  The correct answer is A .
• Question 440: The general formula of an alkyl halide (where X represents the halide) is? Options:
  A) C_nH_2n2X
  B) C_nH_2n + ₁X
  C) C_nH_2n + ₂X
  D) C_nH_2nX
  Show Answer
  The correct answer is B .