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:

  The cost of discharging 6.0g of a divalent metal, X from its salt is ₦12.00. What is the cost of discharging 9.0g of a trivalent metal, Y from its salt under the same condition?

  [X = 63, Y = 27, 1F = 96,500C]

  Options:
  A) N12.00
  B) N27.00
  C) N63.00
  D) N95.00
  Show Answer
  The correct answer is C .
• Question 322: 2H₂S_(g) + SO_2(g) → 3S_(s) + 2H₂O_(I). The above reaction is? Options:
  A) a redox reaction H₂S is the oxidant and SO₂ is the reductant
  B) a redox reaction in which SO₂ is the oxidant and H₂S is the reductant
  C) not a redox reaction because there is no oxidant in reaction equation
  D) not a redox because there is no reductant in the reaction equation
  Show Answer
  The correct answer is B .
• Question 323: Which of the following is a physical change? Options:
  A) The bubbling of chlorine into water
  B) The bubbling of chlorine into a jar contanining hydrogen
  C) The dissolution of sodium chloride in water
  D) The passing of steam over heated iron
  Show Answer
  The correct answer is C .
• Question 324: The pressure on 100 cm³ of oxygen gas at 35°C is 750mm of Hg.What would be the volume of the gas if the pressure is increased to 1000mm of Hg without changing the temperature? Options:
  A) 133.3 cm³
  B) 85 cm³
  C) 75 cm³
  D) 65 cm³
  E) 58.3 cm³
  Show Answer
  The correct answer is C .
• Question 325: On heating anhydrous iron (ll) sulphate, in addition to producing iron (iii) oxide, which of the following is produced? Options:
  A) SO₂ (g) + FeS (s)
  B) SO₃ (g) +FeS(s)
  C) SO₂ (g) + SO₃(g)
  D) SO₂ (g) + H₂S (g)
  E) SO₃(g) + H₂S(g)
  Show Answer
  The correct answer is C .
• Question 326:

  The nucleus of an atom consists of?

  Options:
  A) Electrons and neutrons
  B) Electrons and protons
  C) Protons and neutrons
  D) None of the above
  Show Answer
  The correct answer is C .
• Question 327: Which of these reagents can confirm the presence of a triple bond? Options:
  A) Bromine water
  B) Acidified KMnO₄
  C) Copper (I) chloride
  D) Bromine gas
  Show Answer
  The correct answer is C .
• Question 328: If the relative molecular mass of an element is not a whole number, it can be deduced that the element is Options:
  A) naturally radioactive
  B) abundant in nature
  C) a transition metal
  D) an isotopic mixture
  Show Answer
  The correct answer is D .
• Question 329:

  

  The functional groups present in the compound above are

  Options:
  A) alkene and halo-group
  B) hydroxyl and chloro-group
  C) alkene and chloro-group
  D) hydroxyl and halo-group
  Show Answer
  The correct answer is B .
• Question 330: The nitrogen obtained from air has a density higher than the one from nitrogen-containing compounds because the one from air is contaminated with Options:
  A) water vapour
  B) oxgyen
  C) rare gases
  D) carbon (IV) oxide
  Show Answer
  The correct answer is C .