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 1481: In the periodic table, what is the property that decreases along the periodic and increases down the group? Options:
  A) Atomic number
  B) Electron affinity
  C) Ionization potential
  D) Atomic radius
  Show Answer
  The correct answer is D .
• Question 1482:

  If a given quantity of electricity liberates 0.65g of Zn²⁺, what amount of Hg²⁺ would be liberated by the same quantity of current?

  [Zn = 65, Hg = 201]

  Options:
  A) 1.00g
  B) 2.10g
  C) 4.02g
  D) 8.04g
  Show Answer
  The correct answer is B .
• Question 1483: In the electrolysis of brine, the anode is Options:
  A) platinum
  B) copper
  C) zinc
  D) carbon
  Show Answer
  The correct answer is D .
• Question 1484:

  Which one of the following is not a mixture?

  Options:
  A) Air
  B) Mercury
  C) Milk
  D) Cement
  Show Answer
  The correct answer is B .
• Question 1485: Which of the following statements is TRUE of the complete hydrolysis of a glycerine by sodium hygroxide? Options:
  A) 3 moles ofNaOH are required for each mole of glyceride
  B) 3 moles of glycerol are produced
  C) Only one mole of soap is formed
  D) concentrated H₂SO₄ is essential for the completion of the reaction
  Show Answer
  The correct answer is A .
• Question 1486: How many isomers does pentane have? Options:
  A) 6
  B) 5
  C) 4
  D) 3
  Show Answer
  The correct answer is D .
• Question 1487: Which of these pairs are synthetic and natural macromolecules respectively? Options:
  A) Haemoglobin and nylon, creatine and polyethylene
  B) Nylon and polyethlene, creatine and Haemoglobin
  C) Nylon and creatine, polyethylene and haemoglobin
  D) Polyethylene and creatine, nylon and haemoglobin
  Show Answer
  The correct answer is C .
• Question 1488: Which of the following tests would confirm-unequivocally that a solution X contain the sulphate ion if it gives with Options:
  A) silver nitrates solution, a white precipates insoluble in dilute HNO₃
  B) barium chloride solution, a white precipitate insoluble in dilute H₂SO₄
  C) barium chloride solution, a white precipitate insoluble in dilute HCl
  D) barium chloride solution a white precipitate soluble in dilute ammonia
  E) barium chloride solution a white precipitate insoluble in dilute HCl
  Show Answer
  The correct answer is C .
• Question 1489: Which of the following statements applies during the electroysis of sodium hydroxide sodium hydroxide solution using platinum electrodes? Options:
  A) Na⁺ ions are discharged at the cathode
  B) Hydrogen ions are discharged at the anode
  C) the concentration of sodium hydroxide decrease at both electrode compartments
  D) the concentration of sodium hydroxide increases at the cathode only
  E) the concentration of sodium hydroxide increases at the anode only
  Show Answer
  The correct answer is D .
• Question 1490: The highest rate of production of carbon (lV) oxide can be achieved using Options:
  A) 0.05 mol ^-3HCI and 5g powdered CaCO₃
  B) 0.05 mol ^-3HCI and 5g lump CaCO₃
  C) 0.10 mol ^-3HCI and 5g powdered CaCO₃
  D) 0.025 mol ^-3HCI and 5g powdered CaCO₃
  Show Answer
  The correct answer is C .