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Chemistry Past Questions and Answers

Waec Chemistry Questions

Question 1471:
How many atoms are contained in 0.2moles of nitrogen? \([N_{A} = 6.02 \times 10^{23}]\)
  • A \(1.20 \times 10^{23}\)
  • B \(2.41 \times 10^{23}\)
  • C \(3.62 \times 10^{23}\)
  • D \(4.82 \times 10^{23}\)
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Question 1472:
The strength of metallic bonds depends on the
  • A Charge density of the atoms
  • B Ductility of the metal
  • C Number of valence electrons
  • D Total number of electrons in the atom
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Question 1473:
When zinc is added to AgNO\(_{3}\) solution, crystals of silver forms on the zinc surface. This indicates that zinc is
  • A Oxidised
  • B Reduced
  • C Decomposed
  • D Dissociated
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Question 1474:
The empirical formula of a compound containing 0.067mol Cu and 0.066mol O is [Cu = 63.5, O = 16]
  • A \(Cu_{2}O\)
  • B \(CuO\)
  • C \(CuO_{2}\)
  • D \(CuO_{4}\)
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Question 1475:
The change in the oxidation state of iron in the reaction represented by the equation: \(2FeCl_{3} + H_{2}S \to 2FeCl_{2} + 2HCl + S\) is
  • A +2 to +3
  • B 0 to +2
  • C +3 to +2
  • D +3 to 0
View Answer & Explanation