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 1091:

  

  The diagram above represents an atom of

  Options:
  A) magnesium
  B) helium
  C) chlorine
  D) neon
  Show Answer
  The correct answer is A .
• Question 1092: During a titration experiment, 0.05 moles of carbon (lV) oxide is liberated. What is the volume of gas liberated? Options:
  A) 22.40 dm ³
  B) 11.20 dm ³
  C) 2.24 dm ³
  D) 1.12 dm ³
  Show Answer
  The correct answer is D .
• Question 1093:

  When water drops are added to calcium carbide in a container and the gas produced is passed through a jet and lighted, the resultant flame is called an?

  Options:
  A) Oxyethene
  B) Oxyhydrocarbon flame
  C) Oxyacetylene flame
  D) Oxymethane flame
  Show Answer
  The correct answer is C .
• Question 1094: A mixture contains 20cm³ of hydrogen, 35cm³ of oxygen, 15cm³ of carbon monoxide and 10cm³ of nitrogen at S.T.P. Which of the following gives the mole fraction of hydrogen in this mixture? Options:
  A) 0.02
  B) 0.16
  C) 0.20
  D) 0.25
  E) 20
  Show Answer
  The correct answer is D .
• Question 1095: Group 1 A metals are not found free in nature because they? Options:
  A) are of low melting and boiling points
  B) have weak metallic bonding
  C) conduct electricity and heat
  D) are very reactive
  Show Answer
  The correct answer is D .
• Question 1096: Mortar is NOT used for under-water construction because Options:
  A) it hardens by lose of water
  B) its hardening doe not depend upon evaporation
  C) it requires concrete to harden
  D) it will be washed away by the flow of water
  Show Answer
  The correct answer is A .
• Question 1097:

  Which of the following is the best starting material for the preparation of oxygen? Heating of trioxonitrate (v) with

  Options:
  A) Pb
  B) Zn
  C) Ca
  D) Na
  Show Answer
  The correct answer is A .
• Question 1098: How many unpaired electron(s) are there in the nitrogen sub-levels/ Options:
  A) 3
  B) 2
  C) 1
  D) none
  Show Answer
  The correct answer is A .
• Question 1099:

  MnO^-_4(aq) + Y + 5Fe²⁺_(aq) → Mn²⁺_(aq) + 5Fe²⁺_(aq) + 4H₂O^(l)

  In the equation above, Y is

  Options:
  A) 5H⁺_(aq)
  B) 4H⁺_(aq)
  C) 10H⁺_(aq)
  D) 8H⁺_(aq)
  Show Answer
  The correct answer is D .
• Question 1100: Alloys are best prepared by Options:
  A) Electroplating
  B) Arc-welding
  C) Reducing and mixture of their metallic oxide
  D) Cooling a molten mixture of the metals
  Show Answer
  The correct answer is D .