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 1561: In which of the following reactions is sulphur dioxide acting as an oxidizing agent? Options:
  A) SO ₂ + 2HNO₃ →H₂SO₄ + NO₂ + Heat
  B) 2SO₂ + 2H₂O + O₂→ 2H₂SO₄
  C) SO₂ + 2H₂O + CI₂→ H₂SO₄ + 2HCI
  D) SO₂ + 2H₂S → 3S + 2H₂O
  E) SO₂ + H₂O → H₂SO₃
  Show Answer
  The correct answer is D .
• Question 1562: The metal whose ore can be concentrated by passing it through a magnetic separator is Options:
  A) Zn
  B) Sn
  C) Cn
  D) Ca
  Show Answer
  The correct answer is B .
• Question 1563:

  According to Charles' law, the volume of a gas becomes zero at

  Options:
  A) 0°C
  B) -100°C
  C) -273°C
  D) -373°C
  Show Answer
  The correct answer is C .
• Question 1564: In which of the following are the aqueous solutions of each of the substances correctly arranged in order to decreasing acidity? Options:
  A) Ethanoic acid, milk or magnesia, sodium chloride, hydrochloric acid and sodium hydroxide
  B) Ethanoic acid, hydrochloric acid, milk of magnesia, sodium chloride and sodium chloride and sodium hydroxide
  C) Hydrochloride acid, ethanol acid, sodium chloride, milk of magnesia and sodium hydroxide
  D) Hydrochloride acid, sodium hydroxide sodium chloride, ethanol acid, and milk of magnesia
  Show Answer
  The correct answer is C .
• Question 1565: The condition required for corrosion to take place is the presence of Options:
  A) water and carbon (IV) oxide
  B) water, carbon (IV) oxide and oxygen
  C) oxygen and carbon (IV) oxide
  D) water and oxygen
  Show Answer
  The correct answer is D .
• Question 1566: Copper sulphate solution is electolysed using platinum electrodes A. current of 0.193 amperes is passed for 2hrs. How many grams of copper are deposited? (cu = 63.5, F = 96500 coulombs) Options:
  A) 0.457g
  B) 0.500g
  C) 0.882g
  D) 0.914g
  E) 1.00g
  Show Answer
  The correct answer is A .
• Question 1567: The reaction between ammonia and ethyl ethanoate produces Options:
  A) propanol and ethanamide
  B) propanol and propanamide
  C) ethanol and propanamide
  D) ethanol and ethanamide
  Show Answer
  The correct answer is D .
• Question 1568: The major component of the slag from the production of iron is? Options:
  A) an alloy of calcium and iron
  B) coke
  C) impure iron
  D) calcium trioxosilicate (IV)
  Show Answer
  The correct answer is B .
• Question 1569: 30 cm³ of 0.1 M Al (NO₃)₃ SOLUTION IS RECTED WITH 100cm³ of 0.15M of NaOH solution. Which reactant is in excess, and by now much ? Options:
  A) NaOH solution by 70 cm³
  B) NaOH solution, by 60 cm³
  C) NaOH solution by 40 cm³
  D) Al(NO₃)₃ solution by 20 cm³
  E) Al(NO₃)₃ solution by 10 cm³
  Show Answer
  The correct answer is C .
• Question 1570:

  Na₂S₂O_3(aq) + 2HCl_(aq) → 2NaCl_(aq) + H₂O_(l)

  Which of the following would introduce the greatest increase in the rate of the chemical reaction above?

  Options:
  A) An increase in temperature and decrease in the concentration of the reactant
  B) A decrease in the volume and increase in the pressure of the reactant
  C) A decrease in the temperature and an incease in the concentration of the reactant
  D) An increase in temperature and an increase in the concentration of the reactant
  Show Answer
  The correct answer is D .