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 1831:

  Pure sulphuric acid is a liquid of 1:84 density. What volume of it would be required to prepare 250 cm³ of 2.0 M solution?

  (H = 1, S = 32, O = 16)

  Options:
  A) 2.00
  B) 2.66
  C) 3.00
  D) 3.66
  E) 4.00
  Show Answer
  The correct answer is B .
• Question 1832:

  Cu²⁺_(aq) + 4NH_3(g) ↔ [Cu(NH₃)₄]²⁺_(aq)

  In the reaction above, what is the effect of precipitating Cu²⁺_(aq) as CuS_(s)?

  Options:
  A) NH_3(g) concentration will decrease
  B) more NH_3(g)
  C) The equilibrium will shift to the right
  D) There will be no effect
  Show Answer
  The correct answer is C .
• Question 1833: The enzyme used in the hydrolysis of starch to dextrin and maltose is Options:
  A) amylase
  B) diastatse
  C) invertase
  D) zymase
  Show Answer
  The correct answer is B .
• Question 1834:

  

  The graph above demonstrate the effect of

  Options:
  A) surface area on the rate of reaction
  B) catalyst on the rate of reaction
  C) pressure on the rate reaction
  D) concentration on the rate of reaction
  Show Answer
  The correct answer is A .
• Question 1835: Water molecule can be ligands especially when they are bonded to Options:
  A) alkaline earth metals
  B) alkali metals
  C) transition metals
  D) group VII elements
  Show Answer
  The correct answer is C .
• Question 1836: A mixture of iodine and sulphur crystals can be separated by treatment with Options:
  A) water to filter off sulphur
  B) carbon (IV) suiphide to filter off iodine
  C) ethanoic acid to filter off sulphur
  D) methanol to filter off iodine
  Show Answer
  The correct answer is B .
• Question 1837: Flow of current in electrolytes is due to the movement of Options:
  A) electrons
  B) Holes and electron
  C) Ions
  D) Charges
  Show Answer
  The correct answer is C .
• Question 1838: 5 block elements of the periodic table one made up of Options:
  A) groups 1, 2, 3
  B) groups 1, and 2
  C) group 3
  D) group 3 to 7
  Show Answer
  The correct answer is B .
• Question 1839:

  The hybridization in the compound $C{H}_3-C{H}_2-C\equiv H$ is

  Options:
  A) sp${}^3$ and sp
  B) sp
  C) sp${}^2$
  D) sp${}^3$ and sp${}^2$
  Show Answer
  The correct answer is A .
• Question 1840:

  Chlorine, consisting of two isotopes of mass numbers 35 and 37, has an atomic mass of 35.5.

  The relative abundance of the isotope of mass number 37 is?

  Options:
  A) 20
  B) 25
  C) 50
  D) 75
  Show Answer
  The correct answer is B .