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 1251:

  The shapes of water, ammonia, carbon (iv) oxide and methane are respectively

  Options:
  A) linear, tetrahedral, angular and pyramidal
  B) angular, pyramidal, linear and tetrahedral
  C) pyramidal, linear, tetrahedral and angular
  D) tetrahedral, angular, pyramidal and linear
  Show Answer
  The correct answer is B .
• Question 1252: Magnesium (IV) oxide is known to hasten the decomposition of hydrogen peroxide. Its main action is to? Options:
  A) increase the surface area of the reactants
  B) increase the concntration of the reactants
  C) lower the activation energy for the reaction
  D) lower the heat of reaction, ∆H, for the reaction
  Show Answer
  The correct answer is C .
• Question 1253: When heat is absorbed during a chemical reaction, the reaction is said to be Options:
  A) thermodynamic
  B) exothermic
  C) isothermal
  D) endothermic
  E) thermostatic
  Show Answer
  The correct answer is D .
• Question 1254:

  CH₃COOH_(aq) + OH^-_(aq) ↔ CH₃COO^-_(aq) + H₂O_(l)

  In the reaction above ,CH₃COO^-_(aq) is

  Options:
  A) conjugate base
  B) acid
  C) base
  D) conjugate acid
  Show Answer
  The correct answer is A .
• Question 1255:

  

  Use the solubility curves below to answer questions. If 1 dm³ of a saturated solution of L at 60⁰C is cooled to 25⁰C, what amount in mole will separate out?

  Options:
  A) 0.75
  B) 0.25
  C) 1.00
  D) 0.50
  Show Answer
  The correct answer is A .
• Question 1256: How many cations will be produced from a solution of potassium aluminium tetraoxosulphate (VI)? Options:
  A) 3
  B) 4
  C) 1
  D) 2
  Show Answer
  The correct answer is D .
• Question 1257:

  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 1258: The importance of sodium aluminate (III) in the treatment of water is to Options:
  A) cause coagulation
  B) neutralize acidity
  C) prevent goitre and tooth decay
  D) kill germs
  Show Answer
  The correct answer is A .
• Question 1259:

  SO${}_3$ is not directly dissolved in water in the industrial preparation of H${}_2$SO${}_4$ by the contact process because

  Options:
  A) SO${}_3$ is an acidic gas
  B) Acid is usually added to water and not water to acid
  C) The reaction between SO${}_3$ and water is violently exothermic
  D) SO${}_3$ does not dissolve readily in water
  Show Answer
  The correct answer is C .
• Question 1260: What type of bond exits between an element X with atomic number 12 and Y with atomic number 17? Options:
  A) Electrovalent
  B) Metallic
  C) Covalent
  D) Dative
  Show Answer
  The correct answer is A .