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 641:

  In order to electroplate spoon with silver, the arrangement of the electrolytic cell is?

  Options:
  A) the anode is a silver rod and the cathode is the spoon
  B) the anode is the spoon and the cathode is a silver rod
  C) the electrolyte is silver trioxonitrate(v)( solution and the cathode is a silver rod.
  D) the electrolyte is silver trioxonitrate(v) solution and the anode is the spoon
  Show Answer
  The correct answer is A .
• Question 642: Which of the following classes of organic compounds undergoes rapid oxidation with bromine water? Options:
  A) alcohols
  B) alkenes
  C) carboxylic acids
  D) esters
  E) alkanes
  Show Answer
  The correct answer is B .
• Question 643: Iron galvanized with zinc is cathodically protected from corrosion. This is because? Options:
  A) zinc has a more positive oxidation potential than iron
  B) zinc has less positive oxidation potential than iron
  C) bith have the same oxidation potential
  D) zinc is harder than iron
  Show Answer
  The correct answer is B .
• Question 644:

  

  The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. If the molar mass of X is 36 g, the number of moles of X dissolved at 343 K is

  Options:
  A) 0.2 moles
  B) 0.7 moles
  C) 1.5 moles
  D) 2.0 moles
  E) 3.0 moles
  Show Answer
  The correct answer is B .
• Question 645: A change in temperature of a saturated solution disturb the equilibrium between the Options:
  A) Dissolved solute and the solvent
  B) Solvent and undissolved solute
  C) Dissolved solute and undissolved solute
  D) Dissolved solute and the solution
  Show Answer
  The correct answer is C .
• Question 646:

  

  In the above set up substances X and Y are respectively

  Options:
  A) lime water copper (ll) tetraoxosulphate (lV)
  B) potassium trioxocarbonate and alkaline pyrogallol
  C) potassium hydroxide and alkaline pyrogallol
  D) potassium trioxocarbonate (lV) and concentrated tetraoxosulphate (IV) acid
  Show Answer
  The correct answer is C .
• Question 647: The mathematical expression of PH is Options:
  A) log ₁₀[OH^-]
  B) log ₁₀1/[H ₃ O⁺]
  C) log ₁₀[H ₃ O⁺]
  D) log ₁₀1/[OH ^-]
  Show Answer
  The correct answer is B .
• Question 648: Which of the noble gases has the greatest ionization energy Options:
  A) He
  B) Xe
  C) Ar
  D) Rr
  Show Answer
  The correct answer is A .
• Question 649:

  What is the product of the electrolysis of aqueous sodium chloride (NaCl) using inert electrodes?

  Options:
  A) Hydrogen gas at the cathode and chlorine gas at the anode
  B) Hydrogen gas at the cathode and oxygen gas at the anode
  C) Sodium metal at the cathode and chlorine gas at the anode
  D) Sodium metal at the cathode and oxygen gas at the anode
  Show Answer
  The correct answer is A .
• Question 650: The ability of ionic solids is generally due to the? Options:
  A) negative electron affinity of most atoms
  B) crystal lattice forces
  C) electron pair sharing
  D) positive ionization potentials
  Show Answer
  The correct answer is B .