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 411: The main impurity in iron ore during the extraction of iron is Options:
  A) Silicon (IV) oxide
  B) Carbon (IV) oxide
  C) Calcium trioxosilicate
  D) Sulphur (II) oxide
  Show Answer
  The correct answer is A .
• Question 412:

  An example of a polysaccharide is?

  Options:
  A) Dextrose
  B) Mannose
  C) Glucose
  D) Starch
  Show Answer
  The correct answer is D .
• Question 413:

  What is the chemical structure of soap and detergent molecules?

  Options:
  A) Hydrophilic head and hydrophobic tail
  B) Hydrophilic head and hydrophilic tail
  C) Hydrophobic head and hydrophobic tail
  D) Hydrophilic tail and hydrophobic head
  Show Answer
  The correct answer is A .
• Question 414: In an electrochemical cell, polarization is caused by Options:
  A) Oxygen
  B) Hydrogen
  C) Tetraoxosulphate(IV) acid
  D) Chlorine
  Show Answer
  The correct answer is B .
• Question 415:

  What volume of (dm${}^3$) of water will be added to 10dm${}^3$ of 2.0 mol/dm${}^3$ HCL acid solution to give a final solution of 0.5 mol/dm${}^3$?

  Options:
  A) 30
  B) 40
  C) 20
  D) 50
  Show Answer
  The correct answer is B .
• Question 416: Which of the following substances is a mixture? Options:
  A) granulated sugar
  B) sea water
  C) sodium chloride
  D) Iron fillings
  Show Answer
  The correct answer is B .
• Question 417:

  Which of the following is an example of an endothermic reaction?

  Options:
  A) Combustion of propane (C${}_3$H${}_8$) to produce carbon dioxide (CO${}_2$) and water (H${}_2$O).
  B) Burning of methane (CH${}_4$) in the presence of oxygen
  C) Formation of table salt (NaCl) from sodium (Na) and chlorine (Cl${}_2$).
  D) Decomposition of hydrogen peroxide (H${}_2$O${}_2$) into water (H${}_2$O) and oxygen (O${}_2$).
  Show Answer
  The correct answer is D .
• Question 418: The colour imparted to a flame by calcuium ion is Options:
  A) green
  B) blue
  C) brick-red
  D) yellow
  E) lilac
  Show Answer
  The correct answer is C .
• Question 419:

  Soaps clean surfaces on the principlebased on?

  Options:
  A) viscosity
  B) floatation
  C) elasticity
  D) surface tension
  Show Answer
  The correct answer is D .
• Question 420:

  How many neutrons are present in atom with mass number and atomic number 37 and 17 respectively?

  Options:
  A) 18
  B) 20
  C) 37
  D) 17
  Show Answer
  The correct answer is B .