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 1551:

  117.0g of sodium chloride was dissolved in the solubility in 1.0dm³ of distilled water at 25^oC. Determine the solubility in mol dm^-3 of sodium chloride at that temperature

  [Na = 23, Cl = 35.5]

  Options:
  A) 1.0
  B) 2.0
  C) 3.0
  D) 4.0
  Show Answer
  The correct answer is B .
• Question 1552: When sodium ethanoate is treated with a few drops of concentrated tetraoxosulphate(vi)acid. one of the products is Options:
  A) CH₃COOH
  B) CH₃COOCH₃
  C) CH₃COOC₂H₅
  D) C₂H₅COOCH₃
  Show Answer
  The correct answer is A .
• Question 1553: The formula for ethyl butanoate is Options:
  A) C₃H₇COOC₂H₅
  B) C₂H₅COOC₃H₇
  C) C₄H₉COOC₂H₅
  D) C₂H₅COOC₄H₉
  Show Answer
  The correct answer is A .
• Question 1554:

  In the reaction H_2(g)O $\to$ H_2(g) + 1/2O_2(g)

  ΔH = -2436000 KJ, which of the following has no effect on the equilibrium position?

  Options:
  A) Adding argon to the system
  B) Lowering the temperature
  C) Adding hydrogen to the system
  D) Decreasing the pressure
  E) Increasing the temperature
  Show Answer
  The correct answer is A .
• Question 1555: Consider the following equation H₂O + 2Fe²⁺ + Cl₂ ↔ 2Fe³⁺ + 2Cl^- + H₂O. The only ion which behaves as an oxidising agent is Options:
  A) Fe²⁺
  B) Cl₂
  C) Fe³⁺
  D) Cl^-
  E) H₂O
  Show Answer
  The correct answer is B .
• Question 1556: Which of the following compounds is NOT the correct product formed when the parent metals is heated in air? Options:
  A) Calcium oxide (CaO)
  B) Sodium oxide (Na₂O)
  C) Copper (ll) oxide (CuO)
  D) Tri-iron tetroxide (Fe₃O₄)
  E) Aluminium oxide (Al₂O₃)
  Show Answer
  The correct answer is D .
• Question 1557: If the electron configuration of a element is p1s² 2s² 2P⁵, how many unpaired electron are there? Options:
  A) 2
  B) 8
  C) 1
  D) 4
  Show Answer
  The correct answer is C .
• Question 1558: The radioactive emission with the least ionization power is Options:
  A) $\alpha -particles$
  B) X-rays
  C) $\gamma -rays$
  D) $\beta -rays$
  Show Answer
  The correct answer is C .
• Question 1559:

  Which organic compound is responsible for the characteristic aroma of fruits?

  Options:
  A) Alkane
  B) Alkyne
  C) Ester
  D) Amine
  Show Answer
  The correct answer is C .
• Question 1560: The best treatment for a student who accidentally poured concentrated tetraoxosulphate (VI) acid on his skin in the laboratory is to wash the skin with? Options:
  A) cold water
  B) sodium hydroxide solution
  C) iodine solution
  D) sodium trioxocarbonate (IV) solution
  Show Answer
  The correct answer is B .