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 1:

  A few drop of conc HCL are added to about 10cm${}^3$ of a solution of PH 3.4. The PH of the resulting mixture is?

  Options:
  A) less than 3.4
  B) greater than 3.4
  C) unaltered
  D) the same as that of the pure water
  Show Answer
  The correct answer is A .
• Question 2: In the discovery of protein, the instrument used is Options:
  A) cathode ray tube
  B) glass tube and discharge tube
  C) discharge tube with terminal cathode
  D) discharge tube with central cathode
  Show Answer
  The correct answer is D .
• Question 3: The soft solder used for welding and plumbing is alloy of Options:
  A) lead and tin
  B) iron and tin
  C) lead and zinc
  D) iron and zinc
  Show Answer
  The correct answer is A .
• Question 4:

  What is the IUPAC name for the following compound? HC$\equiv$CCH${}_3$

  Options:
  A) Acetylene
  B) Methyl acetylene
  C) Butanol
  D) Decanoic acid
  Show Answer
  The correct answer is B .
• Question 5: Which of the following separation processes is most likely to yield high quality ethanol (>95%) from palm wine? Options:
  A) Fractional distillation without a dehydrant
  B) simple distillation with a dehydrant
  C) fractional distillation with a dehydrant
  D) column chromatography
  E) evaporation
  Show Answer
  The correct answer is C .
• Question 6:

  CH₂S_(g) + O_2(g) → 2Cn + SO_2(g)

  What is the change in the oxidation number of copper in the reaction?

  Options:
  A) 0 to + 2
  B) 0 to + 1
  C) C + 1 to 0
  D) + 2 to + 1
  Show Answer
  The correct answer is C .
• Question 7:

  

  The IUPAC nomenclature for the compound above is

  Options:
  A) 4-methylpent-1-ene
  B) 3-methylpent-2-ene
  C) 2-methylpent-1ene
  D) 2-methylpent-4-ene
  Show Answer
  The correct answer is A .
• Question 8:

  Sodium reacts vigorously with water to produce

  Options:
  A) Sodium chloride (NaCl) and oxygen gas (O2)
  B) Sodium nitrate (NaNO3) and water (H2O)
  C) Sodium hydroxide (NaOH) and hydrogen gas (H2)
  D) Sodium oxide (Na2O) and hydrogen gas (H2)
  Show Answer
  The correct answer is C .
• Question 9: When a pressure cooker is half filled with water, and heated to boiling point, then the pressure inside the cooker will? Options:
  A) decrease, since only a fraction of the water molecules has changed to vapour
  B) remain constant, because the total number of water molecules has not changed
  C) increase, because the water molecules can now reach every part of the sealed tube
  D) decrease, since water boils under reduced pressure
  E) increase, because the water vapour molecules now strike the walls of the tube more frequently because of their increased velocity
  Show Answer
  The correct answer is E .
• Question 10: The metal that liberates hydrogen from cold water in bubbles only is Options:
  A) Na
  B) K
  C) Ca
  D) Al
  Show Answer
  The correct answer is C .