Question

Use the data given here to calculate the values of delta G^degree _rxn at 25^degree C for the reaction described by the equation A + B double headed arrow C If delta D^degree _rxn and delta S^degree _rxn are both negative values, what drives the spontaneous reaction and in what direction at standard conditions? The spontaneous reaction is entropy-driven to the right. entropy-driven to the left. enthalpy-driven to the left. enthalpy-driven to the right.

Answer 1

$\Delta$ G⁰_f = $\sum$ $\Delta$ G⁰_f  (Product) - $\sum$ $\Delta$ G⁰_f (Reactant)

$\Delta$ G⁰_f = [( $\Delta$ G⁰_f C] - [( $\Delta$ G⁰_f A) + ( $\Delta$ G⁰_f B)]

= [(402.0)] - [(387.7) + (-553.2)]

= [402.0 ] - [-165.5]

= [402.0] + [165.5]

= 567.5

$\Delta$ G⁰_f   = 567.5 KJ/mol

Answer - 567.5 KJ/mol