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 321:

  Diamond is a bad conductor of electricity because its bonding electrons are used in

  Options:
  A) crystal lattice formation
  B) covalent bond formation
  C) metallic bond formation
  D) coordinate bond formation
  Show Answer
  The correct answer is B .
• Question 322: How many moles of (H+) are there in 1 dm³ of 0.5 M solution of H₂SO₄? Options:
  A) 2.0 moles
  B) 1.0 moles
  C) 0.5 mole
  D) 0.25 mole
  Show Answer
  The correct answer is B .
• Question 323: Which one of these compounds will NOT give an oxygen gas on heating? Options:
  A) Manganese dioxide
  B) Hydrogen peroxide
  C) Zinc nitrate
  D) Sodium nitrate
  E) Ammonium nitrate
  Show Answer
  The correct answer is E .
• Question 324: An example of a solid emulsion is Options:
  A) Butter
  B) Hair cream
  C) Milk
  D) Cod-liver oil
  Show Answer
  The correct answer is A .
• Question 325: N₂O_4(g) ↔ 2NO_2(g). Increase in total pressure of the equilibrium reaction above will Options:
  A) produce more of NO_2(g) in the mixture
  B) convert all of N₂O_4(g) to NO_2(g)
  C) have no effect on the concentrations of NO_2(g)and N₂O_4(g)
  D) produce more of N₂O_4(g) in the mixture
  Show Answer
  The correct answer is D .
• Question 326: In the reaction of oxygen with hydrogen to produce water, which of the following statements is true? Options:
  A) One atom of hydrogen reacts with two atoms of oxygen to give one molecule of water
  B) Two atoms of hydrogen react with two atoms of oxygen to give two molecules of water
  C) One molecule of oxygen reacts with one molecule of hydrogen to give two molecules of water
  D) One molecule of hydrogen reaccts with two molecules of oxygen to give three molecules of water
  E) One molecule of oxygen reacts with two molecules of hydrogen to give two molecules of water
  Show Answer
  The correct answer is E .
• Question 327:

  A cell shorthand notation can be written as A / A${}^{+}$ // B${}^{2+}$ /B. The double slash in the notation represents the 

  Options:
  A) electrolyte
  B) electrodes
  C) salt bridge
  D) solid - liquid interface
  Show Answer
  The correct answer is C .
• Question 328:

  

  The data in the table above shows the rate of reaction of nitrogen (ll) oxide with chlorine at 25^oC It can be concluded that doubling the initial concentration of NO increase the rate of reaction by a factor of

  Options:
  A) two
  B) three
  C) four
  D) five
  Show Answer
  The correct answer is C .
• Question 329: Which of the following gases is the most dangerous pollutant? Options:
  A) Hydrogen sulphide
  B) Carbon (lV) oxide
  C) Sulphur (lV) oxide
  D) Carbon (ll) oxide
  Show Answer
  The correct answer is D .
• Question 330: A certain volume of gas at 298k is heated such that its volume and pressure are now four times the original values. What is the new temperature? Options:
  A) 18.6k
  B) 100.0k
  C) 298.0k
  D) 1192.0k
  E) 4768.0k
  Show Answer
  The correct answer is E .