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 2191: Reduction of nitroalkanes, nitrites and amides is a route for the preparation of Options:
  A) amines
  B) alkenes
  C) polymers
  D) detergents
  Show Answer
  The correct answer is A .
• Question 2192: The structural component that makes detergent dissolve more quickly in water than soap is Options:
  A) -SO₃- Na⁺
  B) -COO-Na^-
  C) -SO₄- Na⁺
  D) -COO-K⁺
  Show Answer
  The correct answer is A .
• Question 2193: If an atom is represented as ${}_{11}^{23}X$, which of the following deduction is correct? Options:
  A) it contains 12 protonic
  B) it forms a covalent chloride
  C) its atomic number is 23
  D) it is an alkali metal
  Show Answer
  The correct answer is D .
• Question 2194: Which of the following happens during the electrolysis of molten sodium chloride? Options:
  A) Sodium ion loses an electron
  B) Chlorine atom gains an electron
  C) Chlorine ion gains an electron
  D) Sodium ion is oxidized
  E) Chloride ion is oxidized
  Show Answer
  The correct answer is E .
• Question 2195:

  Which of the following metals is the most essential in the regulation of blood volume, blood pressure and osmotic equilibrium?

  Options:
  A) Zinc
  B) Manganese
  C) Sodium
  D) Iron
  Show Answer
  The correct answer is C .
• Question 2196:

  Na₂CO₃ + 2HCI → 2NaCI + H₂O + CO₂. Using the above equation, what volume of carbondioxide, measured at s.t.p is liberated when 53g of sodium carbonate is dissolved in hydrochloric acid?

  (1 mole of gas occupies 22.4 dm³ at s.t.p)

  (Na = 23, C = 12, O = 16)

  Options:
  A) 44.8 dm³
  B) 11.2 dm³
  C) 100.1 dm³
  D) 3.0 dm³
  E) 22.4 dm³
  Show Answer
  The correct answer is B .
• Question 2197: Chlorine, bromine and iodine resemble each other in that all? Options:
  A) dissolve in alkalis
  B) react violently with hydrogen without heating
  C) displace each other from solutions of their salts
  D) are gases
  E) are liquids
  Show Answer
  The correct answer is A .
• Question 2198: Which of the following results in the fall of acid rain? Options:
  A) Oxides of lead
  B) Particulate matter
  C) Oxides of sulphur
  D) Gaseous hydrocarbon
  Show Answer
  The correct answer is C .
• Question 2199: The maximum number of electrons in the L shell of an atom is Options:
  A) 2
  B) 8
  C) 18
  D) 32
  Show Answer
  The correct answer is B .
• Question 2200: A phenomenon where an element exist in different forms in the same physical state is known as Options:
  A) isomerism
  B) amorphism
  C) allotropy
  D) isotopy
  Show Answer
  The correct answer is C .