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 1661: The metal that liberates hydrogen from cold water in bubbles only is Options:
  A) Na
  B) K
  C) Ca
  D) Al
  Show Answer
  The correct answer is C .
• Question 1662:

  

  In the diagram, the function of the concentrated H₂SO₄ is to

  Options:
  A) purify the gas
  B) dry the gas
  C) liquefty the gas
  D) remove odour
  Show Answer
  The correct answer is B .
• Question 1663: What is the valence shell electron configuration of the element with atomic number 17? Options:
  A) 1s² 2s² 2p⁶ 3s² 3p⁴
  B) 1s² 2s² 2p⁶ 3s² 3p⁵
  C) 2s² 2p⁶
  D) 3s² 3p⁵
  Show Answer
  The correct answer is B .
• Question 1664:

  What is the concentration of a solution containing 2g of NaOH in 100cm³ of solution?
  [Na = 23, O = 16, H = 1]

  Options:
  A) 0.40 mol dm^-3
  B) 0.50 mol dm^-3
  C) 0.05 mol dm^-3
  D) 0.30 mol dm^-3
  Show Answer
  The correct answer is B .
• Question 1665: When sodium hydroxide is heated with ammonium tetraoxosulphate (IV), the gas given off may be collected by? Options:
  A) bubbling it through concentrated H₂SO₂
  B) bubbling it through water and then passing it through calcium oxide
  C) passing it directly through calcium oxide
  D) passing it directly through calcium chloride
  Show Answer
  The correct answer is C .
• Question 1666: A particle that contains 8 proton, 9 neutrons and 7 electrons could be written as? Options:
  A) O
  B) O⁺
  C) O⁺
  D) O^-
  Show Answer
  The correct answer is B .
• Question 1667:

  

  The option above shows the PH changes for the titration of a

  Options:
  A) strong acid versus strong base
  B) weak acid versus strong base
  C) strong acid versus weak base
  D) weak acid versus weak base
  Show Answer
  The correct answer is A .
• Question 1668: Oxygen-demanding waste are considered to be a water pollutant because they? Options:
  A) deplete oxygen which is necessary for the survival of aquatic organism
  B) increase oxygen which is necessary for survival of aquatic organism
  C) increase other gaseous substances which are necessary for the survival of aquatic organisms
  D) deplete other gaseous species which is necessary for the survival of aquatic organisms
  Show Answer
  The correct answer is A .
• Question 1669: CO_g + H₂O_g $\to$ _2g + H_2g $\mathrm{\Delta }$H = -4100J. Which of the following factors favour the formation of hydrogen in the above reaction? i. high pressure. ii. low pressure iii. high temperature iv. use of excess steam Options:
  A) i, iii and iv
  B) iii only
  C) ii, iii and i
  D) iv only
  Show Answer
  The correct answer is D .
• Question 1670:

  The solubility of the solids that dissolves in a given solvent with the liberation of heat will

  Options:
  A) increase with an increase in temperature
  B) decrease with an increase in temperature
  C) decrease with a decrease in temperature
  D) not be affected by changes in temperature
  Show Answer
  The correct answer is A .