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 2121: Synthetic rubber is made by polymerization of? Options:
  A) 2 methyl buta - 1, 3 - diene
  B) 2 methyl buta - 1, 2 - diene
  C) 2 methyl but -1-ene
  D) 2 methyl but-2-ene
  Show Answer
  The correct answer is A .
• Question 2122:

  Which of the following sets of operation will completely separate a mixture of sodium chloride, sand and iodine?

  Options:
  A) addition of water, filtration, evaporation to dryness and sublimation
  B) filtration, evaporation to dryness, addition of water and sublimation
  C) sublimation, filtration, evaporation and addition of water
  D) sublimation, addition of water, filtration and evaporation to dryness
  Show Answer
  The correct answer is A .
• Question 2123: Electronic configuration of an elements 13x in the subsidiary energy level is Options:
  A) $1s^{2}2s^{2}2p^{6}3s^{2}3p^1$
  B) $1s^{2}2s^{2}2p^{4}3p^{1}3s^1$
  C) $1s^{2}2s^{2}2p^{6}3s^{2}3p^3$
  D) $1s^{1}2s^{2}2p^{6}3s^{2}3p^4$
  Show Answer
  The correct answer is A .
• Question 2124: Which of the following bonds exist in crystalline ammonium chloride (NH₄Cl)? Options:
  A) Ionic and covalent
  B) Ionic and co-ordinate
  C) Ionic covalent and co-ordinate
  D) Covalent , co-ordinate and metalllic
  E) Ionic, covalent and metallic
  Show Answer
  The correct answer is C .
• Question 2125: A pair of compounds that can be used to generate a gas which has physiological effect on human beings is Options:
  A) sodium trioxonitrate (V) and calcium chloride
  B) sodium dioxonitrate (III) and ammonium chloride
  C) sodium trioxonitrate (V) and ammonium chloride
  D) sodium dioxonitrate (III) and potassium chloride
  Show Answer
  The correct answer is A .
• Question 2126: A saturated solution of AgCl was found to have a concentration of 1.30 x 10^-5 mol dm^-3. The solubility product of AgCl therefore is? Options:
  A) 1.30 x 10^-5 mol₂ dm^-6
  B) 1.30 x 10^-7 mol₂ dm^-6
  C) 1.69 x 10^-10 mol₂ dm^-6
  D) 2.60 x 10^-12 mol₂ dm^-6
  Show Answer
  The correct answer is C .
• Question 2127: 10cm³ of hydrogen fluoride gas react with 5cm³ of dinitrogen difluoride gas (N²F₂) to form 10₃ of a single gas. Which of the following is the most likely equation of the reaction? Options:
  A) HF + N₂F₂ $\to$ N₂HF₃
  B) 2HF + N₂F₂ $\to$ 2NHF₂
  C) 2HF + N₂F₂ $\to$ N₂H₂F₃
  D) HF + 2N₂F₂ $\to$ N₄HF₂
  Show Answer
  The correct answer is B .
• Question 2128: The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as; Options:
  A) saponification
  B) dehydration
  C) esterification
  D) hydrolysis
  E) hydration
  Show Answer
  The correct answer is C .
• Question 2129:

  

  Use the graph above to answer this question. The mass of a substance, M, liberated at an electrode during electrolysis is proportional to the quantity of electricity, Q passing through the electrolyte. This is represented graphically by.

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is A .
• Question 2130: Equal moles of ethyne and hydrogen iodide react to give Options:
  A) CH₂ = CH₂
  B) CH₂ - CHI
  C) CH₃ - CI
  D) CH₂ = CHI
  Show Answer
  The correct answer is D .