Chemistry · Electrochemical cells: Electrolytic and Galvanic cells, different types of electrodes, electrode potentials including standard electrode potential, half-cell and cell reactions

The number of faradays of electricity required to decompose water (density ) is:

The number of faradays of electricity required to decompose \( 100 \mathrm{ml} \) water (density \( =0.99 \mathrm{gm} / \mathrm{ml} \) ) is:

  • A. 2
  • B. 11
  • C. 100 \)
  • D. 5.5

Step-by-step solution

The decomposition of water: 2H2O → 2H2 + O2. For every mole of H2O, 2 moles of electrons are required (since 4e⁻ per 2H2O). Mass of water = 100 mL × 0.99 g/mL = 99 g. Moles of H2O = 99 g / 18 g/mol = 5.5 mol. Thus, faradays required = 5.5 mol × 2 F/mol = 11 F.
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