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:

  

  In the experiment above, a current was passed for 10 minutes and 0.63g of copper was found to be deposited on the cathode of CuSO₄ cells. The weight of silver deposited on the cathode og AgNO³ cell during the same period would be? [Cu = 63, Ag = 108]

  Options:
  A) 0.54g
  B) 1.08g
  C) 1.62g
  D) 2.16g
  E) 3.24g
  Show Answer
  The correct answer is B .
• Question 322:

  The mass number of a nucleus is?

  Options:
  A) Always less than its atomic number
  B) The sum of the number of protons and neutrons present in the nucleus
  C) Always more than the atomic weight
  D) A fraction
  Show Answer
  The correct answer is B .
• Question 323:

  Which of the following represents the kind of bonding present in ammonium chloride?

  Options:
  A) ionic only
  B) covalent only
  C) ionic and dative covalent
  D) dative covalent
  Show Answer
  The correct answer is C .
• Question 324:

  According to the Kinetic Theory an increase in temperature causes the kinetic energy of particles to

  Options:
  A) decrease
  B) increase
  C) be zero
  D) remain constant
  Show Answer
  The correct answer is B .
• Question 325: How many unpaired electron are in the p-orbitals of a fluorine atom? Options:
  A) 3
  B) $0$
  C) 1
  D) 2
  Show Answer
  The correct answer is C .
• Question 326: A particle that contains a protons, 10 neutrons and 10 electrons is Options:
  A) positive ion
  B) neutral atom of a metal
  C) neutral atom of a non-metal
  D) negative ion
  Show Answer
  The correct answer is D .
• Question 327: What is observed when aqueous solutions of each of tetraoxosulphate (VI) acid, potassium trioxoiodate (V) and potassium iodide are mixed together? Options:
  A) A white precipitate is formed
  B) A green precipitate is formed
  C) The mixture remains colourless
  D) The mixture turns reddish brown
  Show Answer
  The correct answer is D .
• Question 328: S₂O^2-₃ + I₂ → S₂O₆^2- + 2I^-. In reaction above, the oxidizing agent is? Options:
  A) S₂O₃^2-
  B) I₂
  C) S₄O₆^2-
  D) I^-
  Show Answer
  The correct answer is B .
• Question 329: How many faraday of electricity is required to produce 0.25 mole of copper? Options:
  A) 1.00F
  B) 0.01F
  C) 0.05F
  D) 0.50F
  Show Answer
  The correct answer is D .
• Question 330: Water is poured over a white solid and a colourless neutral gas is evolved which burns with a sooty flame. The white solid is? Options:
  A) calcium
  B) calcium oxide
  C) calcium carbide
  D) sodium peroxide
  E) sodium sulphate
  Show Answer
  The correct answer is C .