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 1881: Oxyacetylene flame is used for iron-welding because it Options:
  A) Makes the iron metals solidify very quickly
  B) Combines with oxygen to give a pop sound
  C) Evolves a lot of heat when burnt
  D) Dissociates to produce carbon (IV) oxide and oxygen
  Show Answer
  The correct answer is C .
• Question 1882: The property of chlorine which causes hydrogen chloride to be more ionic than the chlorine molecules is its Options:
  A) electrovalency
  B) electron affinity
  C) electropositivity
  D) electronegativity
  Show Answer
  The correct answer is D .
• Question 1883: A metal X forms two bromides with the formulae XBr₂ and XBr₃. What type of bonding exists between X and bromine in the bromide? Options:
  A) Ionic bonding
  B) Metallic bonding
  C) Dative bonding
  D) Covalent bonding
  Show Answer
  The correct answer is A .
• Question 1884: An isotope has an atomic number of 15 and a mass number of 31. The number of proton it contains is Options:
  A) 16
  B) 15
  C) 31
  D) 46
  Show Answer
  The correct answer is B .
• Question 1885: Which of the following is an electrolyte? Options:
  A) alcohol
  B) sodium ethanoate
  C) solid potassium hydroxide
  D) mercury
  Show Answer
  The correct answer is B .
• Question 1886: An example of a strong electrolyte is? Options:
  A) ethyl acetate
  B) ethanol
  C) glucose
  D) sodium formate
  E) formic acid
  Show Answer
  The correct answer is D .
• Question 1887: Hydrogen diffuses through a porous plug Options:
  A) at the same rate as oxygen
  B) at a slower rate than oxygen
  C) twice as fast as oxygen
  D) three times as fast as oxygen
  E) four times as fast as oxygen
  Show Answer
  The correct answer is E .
• Question 1888:

  The maximum electron in N shell is?

  Options:
  A) 2
  B) 8
  C) 18
  D) 32
  Show Answer
  The correct answer is D .
• Question 1889: Which of the following statements is NOT true of electrovalent compounds? Options:
  A) They are solids
  B) They do not vaporized easily
  C) They usually dissolve in water
  D) The elements forming the compounds normally have their valency electrons in a shared state
  E) They conduct electricity
  Show Answer
  The correct answer is D .
• Question 1890: A property of a colloidal dispersion which a solution does not have is? Options:
  A) the Tyndall effect
  B) homogeneity
  C) osmotic pressure
  D) surface polarity
  Show Answer
  The correct answer is A .