Lecture Notes: Chemical Composition and Electrolysis

Water Composition and Electrolysis

• Water Formula: H₂O (1 oxygen atom and 2 hydrogen atoms)
• Electrolysis Process: Separation of water molecules into oxygen and hydrogen gas using electricity.
  • Balanced chemical equation for electrolysis:
    • 2H₂O → 2H₂ + O₂
• Percent Composition of Water:
  • Formula Mass of Water:
    • Hydrogen: 1 atomic mass unit each (2 atoms total = 2 amu)
    • Oxygen: 16 atomic mass units
    • Total: 18 atomic mass units
  • Percent by Mass:
    • Hydrogen: ~11.1% of the water mass
    • Oxygen: ~88.9% of the water mass
• Electrolysis of 100g Water:
  • Expected yield:
    • 11.1g of hydrogen gas
    • 88.9g of oxygen gas

Composition of Vitamin C

• Chemical Formula: C₆H₈O₆
• Formula Mass:
  • Carbon (C): 6 atoms, 12 amu each, total = 72 amu
  • Hydrogen (H): 8 atoms, 1 amu each, total = 8 amu
  • Oxygen (O): 6 atoms, 16 amu each, total = 96 amu
  • Total Mass: 176 amu
• Percent Composition by Mass:
  • Carbon: 40.9%
  • Hydrogen: 4.5%
  • Oxygen: 54.6%
• Note: Percentages add up to 100%, verifying mass conservation in the molecule.