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 1731: Sulphur exists in six forms in the solid state. This property is known as? Options:
  A) isomerism
  B) allotropy
  C) isotopy
  D) isomorphism
  Show Answer
  The correct answer is B .
• Question 1732: The basic assumption in the kinetic theory of gases that the collisions of the gaseous molecules are perfectly elastic implies that the Options:
  A) forces of attraction and repulsion are in equilibrium
  B) gaseous molecules can occupy any available space
  C) gaseous molecules will continue their motion indefinitely
  D) gases can be compressed
  Show Answer
  The correct answer is C .
• Question 1733:

  Which two gases can be used for the demonstration of the fountain experiment?

  Options:
  A) SO${}_3$ and NH${}_3$
  B) SO${}_2$ and NH${}_3$
  C) HCl and NH${}_3$
  D) SO${}_2$ and HCl
  Show Answer
  The correct answer is C .
• Question 1734:

  If 100 cm³ of oxygen pass through a porous plug in 50 seconds, the time taken for the same volume of hydrogen to pass through the same porous plug is?

  (O = 16, H = 1)

  Options:
  A) 10.0 s
  B) 12.5 s
  C) 17.7 s
  D) 32.0 s
  Show Answer
  The correct answer is B .
• Question 1735: Which of the following is used as an 'anti-knock' in automobile engines? Options:
  A) Tetramethyl silane
  B) Lead tetra-ethyl
  C) Glycerol
  D) n-heptane
  Show Answer
  The correct answer is B .
• Question 1736: Due to the high reactivity of sodium, it is usually stored under Options:
  A) water
  B) mercury
  C) paraffin
  D) phenol
  Show Answer
  The correct answer is C .
• Question 1737:

  Sieving is a technique used to separate mixtures containing solid particles of

  Options:
  A) small sizes
  B) large sizes
  C) different sizes
  D) the same size
  Show Answer
  The correct answer is C .
• Question 1738:

  16.55g of lead (ll) trioxonitrate (V) was dissolved in 100g of distilled water at 20^oC, calculate the solubility of the solute in moldm-³

  [Pb = 207, N = 14, O = 16]

  Options:
  A) 0.05 g
  B) 2.00 g
  C) 1.00 g
  D) none of the above
  Show Answer
  The correct answer is D .
• Question 1739: In which of the following processes is iron being oxidized?1 Fe + H₂SO₄ → FeSO₄ +H₂2 FeSO₄ + H₂S → FeS + H₂SO₄3 2FeCI₂ + Cl₂ → 2FeCl₃4 2FeCl₃ + SnCl₂ + → 2FeCl₂ + SnCl₄ Options:
  A) 1 only
  B) 2 only
  C) 3 only
  D) 1 and 3
  E) 2 and 4
  Show Answer
  The correct answer is D .
• Question 1740:

  

  The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. If the molar mass of X is 36 g, the number of moles of X dissolved at 343 K is

  Options:
  A) 0.2 moles
  B) 0.7 moles
  C) 1.5 moles
  D) 2.0 moles
  E) 3.0 moles
  Show Answer
  The correct answer is B .