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 1201: A change in temperature of a saturated solution disturb the equilibrium between the Options:
  A) Dissolved solute and the solvent
  B) Solvent and undissolved solute
  C) Dissolved solute and undissolved solute
  D) Dissolved solute and the solution
  Show Answer
  The correct answer is C .
• Question 1202: Two equal bulbs, one containing ammonia and the other nitrogen are opened mouth-to-mouth to each other at room temperature. The entropy in the mixture of gases is likely to Options:
  A) remain unchanged
  B) increase
  C) decrease
  D) change
  Show Answer
  The correct answer is B .
• Question 1203: When marble is heated to about 1473 K, another white solid is obtained which reacts vigorously with water to give an alkaline solution. The solution contains? Options:
  A) NaOH
  B) KOH
  C) Mg(OH)₂
  D) Zn(OH)₂
  E) Ca(OH)₂
  Show Answer
  The correct answer is E .
• Question 1204:

  The metal used to recover copper from a solution of copper sulphateis?

  Options:
  A) Na
  B) Ag
  C) Hg
  D) Fe
  Show Answer
  The correct answer is D .
• Question 1205:

  If 1 litre of 2.2M sulphuric acid is poured into a bucket containing 10 litre of water,and resulting solution mixed thoroughly, the resulting sulpuric acid concentration will be?

  Options:
  A) 2.2 M
  B) 1.1 M
  C) O.22 M
  D) 0. 11 M
  E) 0.20 M
  Show Answer
  The correct answer is C .
• Question 1206:

  What is the percentage by mass of oxygen in Al₂(SO₄)₃. 2H₂O?

  [Al = 27, S = 32, H = 1, O = 16]

  Options:
  A) 14.29%
  B) 25.39%
  C) 50.79%
  D) 59.25%
  Show Answer
  The correct answer is D .
• Question 1207: When a few drops of water is added to a blue anhydrous cobalt (II) chloride, the colour changes to Options:
  A) white
  B) pink
  C) red
  D) blue
  Show Answer
  The correct answer is B .
• Question 1208: The uncovered raw food that is sold along major roads is likely to contain some amounts of Options:
  A) Pb
  B) Cu
  C) Ag
  D) Na
  Show Answer
  The correct answer is A .
• Question 1209: A suitable solvent for iodine and nephthalene is Options:
  A) carbon (IV) sulphide
  B) ethanol
  C) water
  D) benzene
  Show Answer
  The correct answer is B .
• Question 1210: An oxide XO₂ has a vapour density of 32. What is the atomic mass of X? Options:
  A) 20
  B) 32
  C) 14
  D) 12
  Show Answer
  The correct answer is B .