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 41: What is the oxidation number of Z in K₃ZCl₆? Options:
  A) -3
  B) +3
  C) -6
  D) +6
  Show Answer
  The correct answer is B .
• Question 42: 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 43:

  H${}^{+}$ + OH${}^{-}$ H${}_2$O

  The equation above illustrates

  Options:
  A) precipitation
  B) hydration
  C) hydrolysis
  D) neutralization
  Show Answer
  The correct answer is D .
• Question 44: A red precipitate of copper (I) carbide is formed when ammonium solution of copper (I) chloride is introduced into Options:
  A) CH₃CH₂CH₂CH₃
  B) CH₂ = CH - CH₂CH₃
  C) CH₃CH₂ - C = CH
  D) CH₃ - C = C - CH₃
  Show Answer
  The correct answer is C .
• Question 45:

  I. H = 1s¹ II. N = 1s² 2s² p³ III. O = 1s² 2s² p⁴ IV. Zn = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰

  From the above, which of the following pairs is like to be paramagnetic?

  Options:
  A) I and II
  B) I and III
  C) I and IV
  D) III and IV
  Show Answer
  The correct answer is A .
• Question 46: Cancerous growths are cured by exposure to Options:
  A) γ - rays
  B) β - rays
  C) α - rays
  D) x - ray
  Show Answer
  The correct answer is D .
• Question 47: Sodium and potassium belong to the same group of the Periodic Table. This is because? Options:
  A) both are metals
  B) both are soft and lighter than water
  C) both form cations by losing electrons
  D) both have identical electronic configuration
  E) both react with water vigorously
  Show Answer
  The correct answer is D .
• Question 48: The efficiency of a solid catalyst to increase reaction rates depends on its Options:
  A) surface area
  B) solubility
  C) concentration
  D) quantity
  Show Answer
  The correct answer is A .
• Question 49: Which of the following represents the balanced equation for the reaction of copper with concentrated trioxonitrate (V) acid? Options:
  A) Cu _(s) + 2HNO _3(aq) → Cu (NO ₃) _2(aq) + H _2(g)
  B) Cu _(s) + 4HNO _3(aq) → Cu (NO ₃) _2(aq) + 2H ₂O ₍₁₎ + 2NO _2(g)
  C) 3Cu _(s) + 8HNO_3(aq) → 3Cu (NO₃)_2(aq) + 4H₂O₍₁₎ + 2NO_(g)
  D) 3Cu_(s) + 4HNO_3(aq) → 3Cu(NO ₃) _2(aq) + 2H ₂O ₍₁₎ + 2NO _(g)
  Show Answer
  The correct answer is B .
• Question 50:

  On the basis of the electrochemical series, which of these ions will show the greater tendency to be discharged at the cathode in an electrolytic cell

  Options:
  A) cu${}^{2+}$
  B) sn${}^{2+}$
  C) fe${}^{2+}$
  D) zn${}^{2+}$
  Show Answer
  The correct answer is A .