Answer to Question #156536 in General Chemistry for ash

Question

1. Consider the reaction:

N2O (g) + NO2 (g) 3 NO (g)     K = 4.4 x 10-19

1. Calculate ΔG° for the reaction at 25°C.
2. Calculate ΔGf° for N2O at 25°C.

Answer 1

N₂O (g) + NO₂ (g)$\to$ 3 NO (g)

ΔG=ΔG° + RTlnQ

At equilibrium, Q= K, and ΔG=0

$\therefore$ ΔG° =- RTlnQ

=-8.314463×298×ln(4.4E-19)

=104726.64Jmol^-1

=104.727kJmol^-1

ΔG°_rxn=$\Sigma$ mΔG°f(product)-$\Sigma$ nΔG°f(reactants)

104726.64Jmol^-1=3ΔG°f(NO)-[ΔG°f(N₂O) + ΔG°f(NO₂)]

=104.727/3

=34.91kJ/mol