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 2211: Which of the following statements is NOT true of carbon monoxide? Options:
  A) CO is poisonous
  B) CO is readily oxidized at room temperature by air to form CO₂
  C) CO may be prepared by reducing CO₂ mixed with coke heated to about 1000^oC
  D) CO may be prepared by heating charcoal with a limited amount of O₂
  E) CO is a good reducing agent
  Show Answer
  The correct answer is B .
• Question 2212: Gunpower is made from charcoal, sulphur and potassium trioxonitrate (V) The salt in the mixture performs the function of Options:
  A) an oxidant
  B) a reductant
  C) a solvent
  D) a catalyst
  Show Answer
  The correct answer is A .
• Question 2213: In the electrolysis of a concentrated solution of sodium chloride using electrodes, which of the following ions are discharged at the cathode and anode respectively? Options:
  A) Na⁺ and Cl^-
  B) Na⁺ and OH^-
  C) H⁺ and OH^-
  D) H⁺ and Cl^-
  Show Answer
  The correct answer is D .
• Question 2214:

  Which of the following pairs cannot be represented with a chemical formula?

  Options:
  A) air and bronze
  B) bronze and sodium chloride
  C) copper and sodium chloride
  D) caustic soda and washing soda
  Show Answer
  The correct answer is A .
• Question 2215: Water is said to be temporarily hard when it contains Options:
  A) Ca (HCO₃)₂ and Mg (HCO₃)₂ salts
  B) Ca (HCO₃)₂ and CaCO₃ SALTS
  C) Mg(HCO₃)₂ and CaSO₄ salts
  D) CaSO₄ and Ca(HCO₃)₂ salts
  Show Answer
  The correct answer is A .
• Question 2216: X_(g) + 3Y_(g) ---- 2z_(g) H = +ve. if the reaction above takes place at room temperature, the G will be Options:
  A) negative
  B) zero
  C) positive
  D) indeterminate
  Show Answer
  The correct answer is D .
• Question 2217:

  Which of the following separation techniques can be employed in obtaining solvent from its solution?

  Options:
  A) Evaporation
  B) Distillation
  C) Filtration
  D) Precipitation
  Show Answer
  The correct answer is B .
• Question 2218: The line observed in the sample hydrogen spectrum are due to emission of? Options:
  A) electrons from the atoms
  B) energy by proton transition
  C) energy by electron transition
  D) neutron from the atom
  Show Answer
  The correct answer is C .
• Question 2219: The reaction that takes place in Daniell cell is Options:
  A) direct combination
  B) redox
  C) double decomposition
  D) neutralization
  Show Answer
  The correct answer is B .
• Question 2220:

  ${}_{11}^{11}Na{+}_0^{1}n{\to }_{11}^{24}Na$

  The reaction above is an example of

  Options:
  A) nuclear fission
  B) nuclear fusion
  C) artificial transmutation
  D) beta decay
  Show Answer
  The correct answer is C .