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 1451:

  What unit of temperature should be used when applying the ideal gas law?

  Options:
  A) Fahrenheit (°F)
  B) Kelvin (K)
  C) Rankine (°R)
  D) Celsius (°C)
  Show Answer
  The correct answer is B .
• Question 1452: Which of the following statements is true about 2-methylpropane and butane Options:
  A) They have different number of carbon atoms
  B) They are members of same homologous series
  C) They have the same boiling points
  D) They have the same chemical properties
  Show Answer
  The correct answer is D .
• Question 1453:

  

  The acidic hydrogen in the compound is the hydrogen attached to carbon number

  Options:
  A) 5
  B) 4
  C) 3
  D) 1
  Show Answer
  The correct answer is D .
• Question 1454: The solvent used for removing grease stain is Options:
  A) turpentine
  B) ammonia solution
  C) ethanol
  D) solution of borax in water
  Show Answer
  The correct answer is B .
• Question 1455: An aqueous solution of an inorganic salt gave white precipitate (i) soluble in excess aqueous NaOH (ii) insoluble in excess aqueous NH₃ (iii) with dilute HCl. The cation present in the inorganic salt is? Options:
  A) Na₄⁺
  B) Ca⁺⁺
  C) Zn⁺⁺
  D) Al⁺⁺⁺
  E) Pb₊₊
  Show Answer
  The correct answer is E .
• Question 1456: One mole of a hydrocarbon contains 48 g of carbon. If it vapour density is 28, the hydrocarbon is? Options:
  A) an alkane
  B) an alkene
  C) an alkyne
  D) aromatic (C = 12, H = 1)
  Show Answer
  The correct answer is B .
• Question 1457: Which of the following compounds of trioxonitrate (V) will decomposes to give dinitrogen (i) oxide and water when heated? Options:
  A) NaNO₃
  B) Zn(NO₃)₂
  C) Cu(NO₃)₂
  D) NH₄NO₃
  Show Answer
  The correct answer is D .
• Question 1458: When ethanol is heated with excess concentrated sulphuric acid, the ethanol is? Options:
  A) oxidized to ethene
  B) polymerized to polyethene
  C) dehydrated to ethene
  D) dehydrated to ethyne
  Show Answer
  The correct answer is C .
• Question 1459:

  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 1460: Which of the following statements is true about 2-methylpropane and butane Options:
  A) They are members of the same homologous series
  B) They have the same boiling point
  C) They have different number of carbon atoms
  D) They have the same chemical properties
  Show Answer
  The correct answer is A .