Question

Calculate the Gibbs free energy change for the chemical reaction: 2H2O (l) → 2H2 (g) + O2 (g)at a temperature of 298 K, given that the standard Gibbs free energies of formation are ΔGf°(H2O) = -237.13 kJ/mol, ΔGf°(H2) = 0 kJ/mol, and ΔGf°(O2) = 0 kJ/mol.

Answer 1

To calculate the Gibbs free energy change  G  for the reaction, we can use the following equation:G = G products  - G reactants First, we need to find the Gibbs free energy of the products and reactants. Since Gf H2  and Gf O2  are both 0 kJ/mol, we only need to consider the Gibbs free energy of formation for H2O.For the reactants, we have 2 moles of H2O:G reactants  = 2 * Gf H2O  = 2 *  -237.13 kJ/mol  = -474.26 kJ/molFor the products, we have 2 moles of H2 and 1 mole of O2, but their Gf values are 0, so:G products  = 2 * Gf H2  + Gf O2  = 2 * 0 kJ/mol + 0 kJ/mol = 0 kJ/molNow, we can calculate the Gibbs free energy change for the reaction:G = G products  - G reactants  = 0 kJ/mol -  -474.26 kJ/mol  = 474.26 kJ/molThe Gibbs free energy change for the reaction 2H2O  l   2H2  g  + O2  g  at 298 K is 474.26 kJ/mol.