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 1951: 2MnO^-₄ + 10Cl^- + 16H⁺ → 2Mn²⁺ + 5Cl₂ + 8H₂O. Which of the substances serves as an oxidizing agent? Options:
  A) Mn²⁺
  B) Cl^-
  C) H₂O
  D) MnO^-₄
  E) Cl₂
  Show Answer
  The correct answer is D .
• Question 1952: Which of the following substances would you see as an indicator in the titration of sodium carbonate solution against hydrochloric acid (complete neutralisation)? Options:
  A) Litmus paper
  B) Phenolphthalein
  C) Methyl orange
  D) Universal indicator
  E) None of these
  Show Answer
  The correct answer is C .
• Question 1953: Which of the following reagents will confirm the presence of unsaturation in a compound? Options:
  A) Fehling's solution
  B) Bromine water
  C) Tollen's reagent
  D) Benedict's solution
  Show Answer
  The correct answer is B .
• Question 1954: Which of the following statements is correct about the periodic table? Options:
  A) elements in the same period have the same number of valence electrons
  B) the valence electrons of the elements in the same period increase progressively 'across the period
  C) elements in the same group have the same number of electron shell
  D) the non-metallic properties of the elements tend to decrease across each period
  Show Answer
  The correct answer is B .
• Question 1955: Which of the following electron configurations indicates an atom with the highest ionization energy? Options:
  A) 2,8,7
  B) 2,8,8,1
  C) 2,8,8,2
  D) 2,8,8,7
  Show Answer
  The correct answer is A .
• Question 1956: A solid begins to melt when? Options:
  A) constituent particles acquires a greater kinetic energy
  B) energy of vibration of particles of the solid is less than the intermolecular forces
  C) constituent particles acquires energy above the average kinetic energy
  D) energy of vibration of particles of the solid equals the intermolecular forces
  Show Answer
  The correct answer is A .
• Question 1957:

  

  Use the figure above to answer this question. Which of the following compounds is an isomer of the compound

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is D .
• Question 1958: In general, an increase in temperature increases the solubility of a solute in water because? Options:
  A) more solute molecules collide with each other
  B) most solutes dissolve with the evoltion of heat
  C) more solute molecules dissociate at hihger temperatures
  D) most solutes dissolve with absorption of heat
  Show Answer
  The correct answer is C .
• Question 1959: Which of the following will change when a catalyst is added to a chemical reaction? Options:
  A) The activation energy
  B) The potential energy of the reactants
  C) The heat of the reaction
  D) the potential energy of the product
  Show Answer
  The correct answer is A .
• Question 1960:

  The reactivity of fluorine is due to?

  Options:
  A) its high electro negativity
  B) small size of fluorine atom
  C) availability of D-orbitals
  D) strong f-f bond
  Show Answer
  The correct answer is A .