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 521: A primary amide is generally represented by the formula Options:
  A) RCOOR
  B) RCONH ₂
  C) RCONHR
  D) RCONR ₂
  Show Answer
  The correct answer is B .
• Question 522: What is the formula of sodium gallate if gallium (Ga)shows an oxidation number of + 3? Options:
  A) NaGaO₃
  B) Na₂Ga(OH)₃
  C) NaGa(OH)₃
  D) NaGa(OH)₄
  E) NaGaO
  Show Answer
  The correct answer is D .
• Question 523:

  In which of the following will hydrogen form ionic compound?

  Options:
  A) HCL
  B) NaH
  C) NH${}_3$
  D) CH${}_4$
  Show Answer
  The correct answer is B .
• Question 524:

  

  In the diagram above, gas X is

  Options:
  A) hydrogen
  B) chlorine
  C) oxygen
  D) hydrogen chloride
  Show Answer
  The correct answer is C .
• Question 525: Water for town supply is chlorinate to make it free from Options:
  A) bad colour
  B) bacteria
  C) temporary hardness
  D) permanent hardness
  Show Answer
  The correct answer is B .
• Question 526:

  The general formula for the Alkanals is?

  Options:
  A) R${}_2$CO
  B) RCHO
  C) ROH
  D) RCOOR
  Show Answer
  The correct answer is B .
• Question 527:

  What is the state of matter in which particles are widely spaced and move freely with high kinetic energy?

  Options:
  A) Liquid
  B) Solid
  C) Plasma
  D) Gas
  Show Answer
  The correct answer is D .
• Question 528:

  Mg²⁺_(aq) + 2e^->_(aq) → Mg_(s)E°_(volts) = 2.370

  Zn²⁺_(aq) + 2e^->_(aq) → Zn_(s)E°_(volts) = -0.763

  Cds²⁺_(aq) + 2e^->_(aq) → Cd_(s)E°_(volts) = 0.403

  Cu²⁺_(aq) + 2e^->_(aq) → Cu_(s)E°_(volts) = 0.340

  In the electrochemical series above, the strongest reducing agents is?

  Options:
  A) Cu _(s)
  B) Cd_(s)
  C) Znsub>(s)
  D) Mg_(s)
  Show Answer
  The correct answer is D .
• Question 529:

  Which of the following types of alkanols undergo oxidation to produce alkanoic acids.I. Primary alkanols

  II. Secondary alkanols

  III. Tertiary alkanols

  Options:
  A) I, II and III
  B) I and II only
  C) III only
  D) I only
  Show Answer
  The correct answer is D .
• Question 530: The allotropy of carbon used in the decolourization of sugar is Options:
  A) Graphite
  B) Soot
  C) Charcoal
  D) Lampblack
  Show Answer
  The correct answer is C .