Question

What is the standard Gibbs free energy change at 298 K for the reaction A + 2B → 2C if the standard Gibbs free energy of formation for A, B, and C are 100 kJ/mol, -50 kJ/mol, and -120 kJ/mol, respectively?

Answer 1

To calculate the standard Gibbs free energy change  G  for the reaction A + 2B  2C, we can use the following equation:G =  Gf products   -  Gf reactants  where Gf represents the standard Gibbs free energy of formation for each substance.For this reaction, the equation becomes:G = [2 * Gf C ] - [Gf A  + 2 * Gf B ]Now, we can plug in the given values for the standard Gibbs free energy of formation for A, B, and C:G = [2 *  -120 kJ/mol ] - [100 kJ/mol + 2 *  -50 kJ/mol ]G =  -240 kJ/mol  -  100 kJ/mol - 100 kJ/mol G = -240 kJ/molSo, the standard Gibbs free energy change for the reaction A + 2B  2C at 298 K is -240 kJ/mol.