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 1391:

  What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?

  Options:
  A) 8.0g
  B) 16.0g
  C) 36.0g
  D) 72.0g
  Show Answer
  The correct answer is D .
• Question 1392: Which of the following raw materials would be required from the smelting of iron ore in a blast furnace? Options:
  A) CaCO ₃
  B) Zn(NO₃)₂
  C) CuSO₄
  D) AICI₃
  E) CaSO₄
  Show Answer
  The correct answer is A .
• Question 1393: POlyvinyl chloride is used to produce Options:
  A) bread
  B) pencils
  C) ink
  D) pipes
  Show Answer
  The correct answer is D .
• Question 1394:

  Zn + 2HCL ZnCl${}_2$ + H${}_2$

  What happens to zinc in the above reaction?

  Options:
  A) oxidized
  B) a reactant
  C) reduced
  D) a metal
  Show Answer
  The correct answer is A .
• Question 1395: A major process involved in the softening of hard water is the? Options:
  A) conversation of a soluble calcium salt to its trioxoncarbonate (lV)
  B) decomposition of calcium rioxocarbonate (lV)
  C) conversion of an insoluble calcium salts to its trioxocarbonate (lV)
  D) oxidation of calcium atoms to its ions
  Show Answer
  The correct answer is A .
• Question 1396: In which of the following processes is iron being oxidized?1 Fe + H₂SO₄ → FeSO₄ +H₂2 FeSO₄ + H₂S → FeS + H₂SO₄3 2FeCI₂ + Cl₂ → 2FeCl₃4 2FeCl₃ + SnCl₂ + → 2FeCl₂ + SnCl₄ Options:
  A) 1 only
  B) 2 only
  C) 3 only
  D) 1 and 3
  E) 2 and 4
  Show Answer
  The correct answer is D .
• Question 1397:

  The process by which salt and water reacted in a limited way to form an acid or abase is?

  Options:
  A) Neutral process
  B) Basic acidic process
  C) Hydrolysis
  D) Sublimation
  Show Answer
  The correct answer is C .
• Question 1398: The Avogadro number of 24g of magnesium is the same as that of Options:
  A) 1g of hydrogen molecules
  B) 16g of oxygen molecules
  C) 32g of oxygen molecules
  D) 35.5g of chlorine molecules
  Show Answer
  The correct answer is C .
• Question 1399: The formula CH₂ for ethanoic acid is regarded as its Options:
  A) Molecular formula
  B) General formula
  C) Empirical formula
  D) Structural formula
  Show Answer
  The correct answer is C .
• Question 1400: Which of the following reactions does not take place in the smelting of iron in a blast furnace? Options:
  A) CaCO_3(s) CaO_(s) + CO_2(g)
  B) C_(s) + O_2(g) CO_2(g)
  C) 3FeCO_(s) + 2OCO_2(g) FeO_4(s)
  D) SiO_2(s) + CaO_(s) CaCO_3(s)
  E) CO_2(g) + C_(s) 2CO_(g)
  Show Answer
  The correct answer is C .