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 621: A suitable solvent for iodine and nephthalene is Options:
  A) carbon (IV) sulphide
  B) ethanol
  C) water
  D) benzene
  Show Answer
  The correct answer is B .
• Question 622: which of the following gives a precipitate when treated with NaOH solution? Options:
  A) AlCl₃
  B) NH₄Cl
  C) Na₂CO₃
  D) CH₃COONa
  Show Answer
  The correct answer is A .
• Question 623:

  (1/2)Zn²⁺_(aq) + e^- → (1/2) Zn_(s)

  In the reaction above, calculate the quantity of electricity required to discharge zinc.

  [F = 96 500 C mol^-1]

  Options:
  A) 0.965 * 10₄C
  B) 4.820 * 10₄C
  C) 9.650 * 10₄C
  D) 48.200 * 10₄C
  Show Answer
  The correct answer is C .
• Question 624: The experiment that showed that atoms have tiny positively charged nucleus was first carried out by Options:
  A) Moseley
  B) Rutherford
  C) Millikan
  D) Dalton
  Show Answer
  The correct answer is B .
• Question 625:

  Proteins in acid solution undergo?

  Options:
  A) Substitution
  B) Fermentation
  C) Hydrolysis
  D) Polymerisation
  Show Answer
  The correct answer is C .
• Question 626: In which of the following is the oxidation number of sulphur equal to -2? Options:
  A) S₈
  B) H₂S
  C) SO ₂
  D) SO ₃^2-
  Show Answer
  The correct answer is B .
• Question 627:

  

  Choose the correct answer in the option above.

  Which of the following is a primary amine?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is B .
• Question 628: A catalyst increase the rate of a chemical reaction by providing a path that Options:
  A) raise the activiation energy
  B) increase the temperature
  C) lowers the activation energy
  D) increase the concentration
  Show Answer
  The correct answer is C .
• Question 629: The scale of a chemical balance is made of iron plate and coated with copper electrolytically because Options:
  A) iron is less susceptible to corrosion than copper
  B) copper is twice as less susceptitible to corrosion as iron
  C) copper is less susceptible to corrosion than iron
  D) copper and iron are equally susceptible to corrosion
  Show Answer
  The correct answer is C .
• Question 630: A piece of sea shell, when dropped into a dilute solution of hydrochloric acid, produces a colourless, odourless gas which turns clear limewater milky. The sea shell contains Options:
  A) sodium chloride
  B) ammonium nitrate
  C) calcium carbonate
  D) calcium chloride
  E) magnesium chloride
  Show Answer
  The correct answer is C .