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 1911:

  Liquid black soap is made by boiling palm oil with liquid extract of ash. The function of the ash is to provide the

  Options:
  A) Acid
  B) Ester of alkanoic acid
  C) Alkali
  D) Alkanol
  Show Answer
  The correct answer is C .
• Question 1912: An organic compound reacted with bromine water to give a colourless solution. The compound is probably an Options:
  A) alkene
  B) alkanal
  C) alkyne
  D) alkanone
  Show Answer
  The correct answer is C .
• Question 1913: Hardening of an oil may be achieved by? Options:
  A) boiling the oil with water
  B) boiling the oil with a catalyst
  C) treating the oil with sodium hydroxide
  D) treating the oil with hydrogen and catalyst
  E) distilling oil under reduced pressure
  Show Answer
  The correct answer is D .
• Question 1914: An example of element that can catenate is Options:
  A) bromine
  B) nitrogen
  C) chlorine
  D) carbon
  Show Answer
  The correct answer is D .
• Question 1915: A gas that can behave as a reducing agent towards chlorine and as an oxidizing agent toward hydrogen sulphide is Options:
  A) O₂
  B) NO
  C) SO₂
  D) NH₃
  E) CO₂
  Show Answer
  The correct answer is C .
• Question 1916:

  A basic postulate of the kinetic theory of gases is that the molecules of a gas move in straight lines between collisions. This implies that

  Options:
  A) collisions are perfectly elastic
  B) forces of repulsion exist
  C) forces of repulsion and attraction are in equilibrium
  D) collisions are inelastic
  Show Answer
  The correct answer is B .
• Question 1917: The enzyme used in the hydrolysis of starch to dextrin and maltose is Options:
  A) Zymase
  B) Sucrase
  C) Amylase
  D) Lactase
  Show Answer
  The correct answer is C .
• Question 1918: Ethanol reacts with aqueous sodium mono-oxoio date (l) to give a bright yellow solid with a characteristic smell. The product is? Options:
  A) trichloromethane
  B) triodomethane
  C) iodoethane
  D) ethanal
  Show Answer
  The correct answer is B .
• Question 1919: How much of magnesium is required to react with 260cm³ of 0.5 M HCl? [Mg = 24] Options:
  A) 0.3g
  B) 1.5g
  C) 2.4g
  D) 3.0g
  Show Answer
  The correct answer is B .
• Question 1920: Which of the following represent hybridization in ethyne? Options:
  A) Sp²
  B) Sp²d
  C) Sp³
  D) Sp
  Show Answer
  The correct answer is D .