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 1901: If the relative molecular mass of an element is not a whole number, it can be deduced that the element is Options:
  A) naturally radioactive
  B) abundant in nature
  C) a transition metal
  D) an isotopic mixture
  Show Answer
  The correct answer is D .
• Question 1902: The colour of litmus in an alkaline medium is Options:
  A) Red
  B) Yellow
  C) Pink
  D) Blue
  Show Answer
  The correct answer is D .
• Question 1903: What volume of 11.0 M hydrochloric acid must be dilute to obtain 1 dm³ of 0.05 M acid? Options:
  A) 0.05 dm³
  B) 0.10 dm³
  C) 0.55 dm³
  D) 11.0 dm³
  Show Answer
  The correct answer is A .
• Question 1904: A solution which on treatment with hydrochloric acid produces a colourless, odourless gas which turns lime water milky is most likely to be a Options:
  A) trioxonitrate (V)
  B) chloride
  C) trioxocarbonate (IV)
  D) hydroxide
  Show Answer
  The correct answer is C .
• Question 1905:

  C₂H₅OH_(aq) → Y

  If the above reaction takes place in conc. H₂SO₄ at 180^o, Y represents

  Options:
  A) CH₄
  B) C₂H₅COOH
  C) C₂H₄
  D) CH₃OCH₃
  Show Answer
  The correct answer is C .
• Question 1906: An elements X with relative atomic mass 16.2 contains two isotopes ¹⁶₈X with relative abundance of 90% and ^m₈X with relative abundance of 10%. The value of m is Options:
  A) 16
  B) 18
  C) 12
  D) 14
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  The correct answer is B .
• Question 1907: A characteristic of the alkane family is Options:
  A) Addition reaction
  B) Elimination reaction
  C) Substitution reaction
  D) Neutralization reaction
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  The correct answer is C .
• Question 1908: How many valence electrons are contained in the element represented ³¹₁₅P? Options:
  A) 3
  B) 5
  C) 15
  D) 31
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  The correct answer is B .
• Question 1909: What amount of mercury would be liberated if the same quantity of electricity that liberates 0.65g of zinc is applied? Options:
  A) 2.01g
  B) 1.00g
  C) 4.02g
  D) 8.04g
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  The correct answer is C .
• Question 1910: The oxidation state of oxygen in tetraoxosulphate (VI) acid is Options:
  A) -4
  B) -2
  C) +4
  D) -8
  Show Answer
  The correct answer is B .