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 921:

  If a solution contains 4.9g of tetraoxosulphate (VI) acid, calculate the amount of copper (II) oxide that will react with it

  [Cu = 64, O = 16, S = 32, H = 1]

  Options:
  A) 0.8g
  B) 4.0g
  C) 40.0g
  D) 80.0g
  Show Answer
  The correct answer is B .
• Question 922:

  

  The IUPAC nomenclature of the structure is

  Options:
  A) 3-chloro-3-methylbutane
  B) 2,2,-dichloro-3-methylbutane
  C) 3-methylchlorobutane
  D) 2-chloro-2-methylbutane
  Show Answer
  The correct answer is D .
• Question 923: Which of the following processes NOT lead to a chemical change? Options:
  A) Strirring iron in sulphur (IV) acid
  B) Stirring sodium carbonate in water
  C) Stirring glucose in concentrated sulphur (IV) acid
  D) Mixing sulphur (IV) acid with potassium carbonate
  E) Titrating an acid against base
  Show Answer
  The correct answer is B .
• Question 924:

  C₂H_4(g) + H_2(g) → C₂H_6(g) ΔH = -137kJ mol_-1

  The reaction represented above is

  Options:
  A) exothermic
  B) spontaneous
  C) endothermic
  D) in equilibrium
  Show Answer
  The correct answer is A .
• Question 925: ${}_{88}^{226}Ra$ → ${}_{86}^{x}Rn$ + alpha particle Options:
  A) 226
  B) 220
  C) 227
  D) 222
  Show Answer
  The correct answer is D .
• Question 926:

  

  The compound above exhibits

  Options:
  A) geometric isomerism
  B) optical isomerism
  C) structural isomerism
  D) positional isomerism
  Show Answer
  The correct answer is B .
• Question 927:

  Why is water often referred to as the "universal solvent"?

  Options:
  A) Water is the most abundant substance on Earth
  B) Water is essential for all living organisms.
  C) Water is involved in many chemical reactions
  D) Water can dissolve a wide variety of substances due to its polar nature
  Show Answer
  The correct answer is D .
• Question 928: The atomic numbers of two elements X and Y are 12 and 19 respectively. The bond of these two elements is? Options:
  A) ionic
  B) covalent
  C) neutral
  D) co-ordinate
  Show Answer
  The correct answer is B .
• Question 929: Elements X and Y have electronic configurations 1s²2s²2p⁶ and 1s²2s²2p⁶3s²3p¹ respectively. When they combine, the formula of the compound formed is Options:
  A) XY
  B) YX
  C) X₂Y₃
  D) Y₂X₃
  Show Answer
  The correct answer is D .
• Question 930: What is the percentage of sulphur in sulphur (IV) oxide? Options:
  A) 66%
  B) 25%
  C) 40%
  D) 50%
  Show Answer
  The correct answer is D .