At 298 ,K, the decomposition of gaseous dinitrogen tetroxide is represented by the…

CHEMISTRY · Multi-part · A Level · Chemistry · Thermodynamics · Thermodynamics

Problem

At 298\,K, the decomposition of gaseous dinitrogen tetroxide is represented by the balanced equation

\mathrm{N_2O_4(g) \rightarrow 2\,NO_2(g)}

For this process the standard Gibbs free‐energy change is

\Delta G^\circ = +4.8\;\text{kJ\,mol}^{-1}

. (a) Describe qualitatively how both the sign and magnitude of

\Delta G^\circ

will change if the reaction is written in the opposite direction. (b) Explain how the value of the equilibrium constant

K

would be affected by writing the reaction in the opposite direction. (c) The reaction is frequently written in the form

\tfrac12\,\mathrm{N_2O_4(g)} \rightarrow \mathrm{NO_2(g)}

. Explain, without performing numerical calculations, how the

\Delta G^\circ

and

K

values for this half-scaled equation compare with those for the original equation.