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 1191: Which of the following equations represents an oxidizing action of sulphur dioxide? Options:
  A) SO₂ + 2HNO₂ → H₂SO₄ + 2NO₂ + heat
  B) 2SO₂ + 2H₂O + O₂ → 2H₂SO₄
  C) SO₂ + 2H₂O + CI₂ → H₂SO₄ + 2HCI
  D) SO₂ + 2H₂S → 3S + 2H₂O
  E) K₂Cr₂O₇ + H₂SO₄ + 3SO₂ → K₂SO₄ + Cr₂(SO₄)₃ + H₂O
  Show Answer
  The correct answer is D .
• Question 1192:

  Which of the following conditions will most enhance the spontaneity of a reaction?

  Options:
  A) $\mathrm{\Delta }$H is negative and greater than T$\mathrm{\Delta }$S
  B) $\mathrm{\Delta }$H is negative and $\mathrm{\Delta }$S = 0
  C) $\mathrm{\Delta }$H is positive and less than T$\mathrm{\Delta }$S
  D) $\mathrm{\Delta }$H is positive and equal to T$\mathrm{\Delta }$S
  Show Answer
  The correct answer is A .
• Question 1193:

  32g of anhydrous copper(ii)tetraoxosulphate(vi) dissolved in 1dm${}^3$ of water generated 13.0kj of heat. The heat solution is?

  Options:
  A) 26.0kj/mol
  B) 65.0kj/mol
  C) 130.0kj/mol
  D) 260.0kj/mol
  Show Answer
  The correct answer is B .
• Question 1194: Hydrogen is readily released when dilute hydrochloric acid reacts with Options:
  A) Cu
  B) Na
  C) Au
  D) Ag
  Show Answer
  The correct answer is B .
• Question 1195: The postulate of Dalton's atomic theory which still holds is that Options:
  A) atoms can neither be created nor destroyed
  B) the particles of the same element are exactly alike
  C) particles of different elements combine in simple whole number ratio
  D) all elemets are made of small indivisible particles
  Show Answer
  The correct answer is A .
• Question 1196: A major effect of oil pollution in coastal waters is the? Options:
  A) destruction of marine life
  B) desalination of the water
  C) increase in the acidity of the water
  D) detoxification of the water
  Show Answer
  The correct answer is C .
• Question 1197: A difference between chemical and physical change is that in a chemical change Options:
  A) oxygen is consumed
  B) heat is supplied
  C) the reversible process occurs
  D) a new substance is formed
  Show Answer
  The correct answer is D .
• Question 1198: Which of the following is an electrolyte? Options:
  A) alcohol
  B) sodium ethanoate
  C) solid potassium hydroxide
  D) mercury
  Show Answer
  The correct answer is B .
• Question 1199:

  Burning magnesium ribbon in air removes which of the following

  (i) oxygen (ii) nitrogen (iii) argon and (iv) carbon(iv)oxide?

  Options:
  A) i and iv only
  B) i, ii, iii and iv only
  C) i only
  D) i and ii only
  Show Answer
  The correct answer is C .
• Question 1200: Which of the following is the correct order of decreasing activity of the metals Fe, Ca, Al and Na? Options:
  A) Fe> Ca> Al> Na
  B) Na> Ca> Al> Fe
  C) Al> Fe> Na> Ca
  D) Ca> Na> Fe>, Al
  Show Answer
  The correct answer is B .