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 21: Which of the following contains two amphoteric oxides? Options:
  A) sodium oxide, Zinc oxide , Magnesium oxide
  B) Aluminium oxide, Calcium oxide, Zinc oxide
  C) Potassium oxide, Lithium oxide, Carbon monoxide
  D) Silver oxide, Lead oxide, Sodium oxide
  E) Sulphur dioxide, Aluminium oxide, Carbon monoxide
  Show Answer
  The correct answer is B .
• Question 22: Calculate the volume of 0.5 mol dm^-3 H₂So₄ that is neutralized by 25 cm³ of 0.1 mol dm^-3 NaOH Options:
  A) 5.0 cm³
  B) 2.5 cm³
  C) 0.4 cm³
  D) 0.1 cm³
  Show Answer
  The correct answer is B .
• Question 23:

  

  The diagram above represent the electron sub-level for

  Options:
  A) carbon
  B) nitrogen
  C) oxygen
  D) flourine
  Show Answer
  The correct answer is C .
• Question 24:

  

  In the diagram above, R is a mixture of

  Options:
  A) potassium tetraxochlorate (VII) and concentrated H₂SO₄
  B) potassium trioxochlorate (V) and concentrated H₂SO₄
  C) potassium tetratoxomanganate (VII) and concentrated HCI
  D) manganes (IV) oxide and concentrated HCI
  Show Answer
  The correct answer is D .
• Question 25: What is the correct IUPAC name for NO₂^-? Options:
  A) Dioxonitrate (IV) ion
  B) Trioxonitrate (III) ion
  C) Trioxonitrate (IV) ion
  D) Dioxonitrate (II) ion
  Show Answer
  The correct answer is D .
• Question 26:

  NH₃ + H₃O⁺

  → NH₄⁺ + H₂O. It may be deduced from the reaction above that?

  Options:
  A) a redox reaction has occurred
  B) H₃O⁺ acts as an oxidizing agent
  C) H₃O⁺ acts as an acid
  D) water acts as ab acid
  Show Answer
  The correct answer is C .
• Question 27: Pure solvents are obtained by Options:
  A) Distillation
  B) Condensation
  C) Extraction
  D) Evaporation
  Show Answer
  The correct answer is A .
• Question 28: Alkanes Options:
  A) are all gases
  B) have the general formula C_nH_2n + ₂O
  C) contain only carbon and hydrogen
  D) are usually soluble in water
  E) are usually active compounds
  Show Answer
  The correct answer is C .
• Question 29: Which of the following acts as both a reducing and an oxidizing agent? Options:
  A) H₂
  B) SO₂
  C) H₂S
  D) C
  Show Answer
  The correct answer is B .
• Question 30:

  

  Carbon (ll) oxide may be collected as shown above because it

  Options:
  A) is heavier than air
  B) is less dense than air
  C) is insoluble in water
  D) burns in oxygen to form carbon (IV) oxide
  Show Answer
  The correct answer is C .