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 361: Ordinary glass is manufactured from silica, CaCO₃ and Options:
  A) Na₂CO₃
  B) K₂CO₃
  C) K₂SO₄
  D) NaHCO₃
  Show Answer
  The correct answer is A .
• Question 362: A hydrocarbon X with a molar mass of 26 consists of 92.3% carbon. What is its molecular formular Options:
  A) C₂H₂
  B) C₃H₃
  C) C₄H₄
  D) C₅H₅
  Show Answer
  The correct answer is A .
• Question 363:

  At 2.0 atm pressure, the volume of a gas is 4.0 L. If the pressure is reduced to 1.0 atm while keeping the temperature constant, what will be the new volume of the gas?

  Options:
  A) 2.0 L
  B) 6.0 L
  C) 8.0 L
  D) 4.0 L
  Show Answer
  The correct answer is C .
• Question 364: When steam is passed over red-hot carbon, the substances produced are Options:
  A) Hydrogen and trioxocarbonate (IV) acid
  B) Hydrogen, oxygen and carbon (IV) oxide
  C) Hydrogen and carbon (II) oxide
  D) Hydrogen and carbon (IV) oxide
  Show Answer
  The correct answer is C .
• Question 365:

  

  It can be deduced that the rate of the reaction

  Options:
  A) for bath l is higher than path ll
  B) for path ll is higher than path l
  C) is the same for both paths at all temperatures
  D) depends on the values of both x and y at all pressures
  Show Answer
  The correct answer is B .
• Question 366: The ability of carbon to form long chains is referred to as Options:
  A) Alkylation
  B) Acylation
  C) Carbonation
  D) Catenation
  Show Answer
  The correct answer is D .
• Question 367:

  

  The compound above exhibits

  Options:
  A) geometric isomerism
  B) optical isomerism
  C) structural isomerism
  D) positional isomerism
  Show Answer
  The correct answer is B .
• Question 368:

  2X_(aq) + MnO_2(s) + 4H⁺_(aq) → X_2(g) + Mn²⁺_(aq) + 2H₂O.

  The reaction above can be used for the laboratory preparation of all halogens except fluorine because it is?

  Options:
  A) a poisionous gas
  B) an oxidizing agent
  C) electronegative in nature
  D) highly reactive
  Show Answer
  The correct answer is D .
• Question 369: When a current I was passed through an electrolyte solution for 40 minutes, a mass X g of a univalent metal was deposited at the cathode. What mass of the metal will be deposited when a current 2I is passed through the solution for 10 minutes? Options:
  A) X/4 g
  B) X/2 g
  C) 2X g
  D) 4X g
  Show Answer
  The correct answer is B .
• Question 370:

  

  In the graph above, the activation energy of the catalyzed reaction is

  Options:
  A) 100KJ
  B) 300KJ
  C) 250KJ
  D) 200KJ
  Show Answer
  The correct answer is A .