Chapter 23, Problem 23.19P

Interpretation Introduction

Interpretation:

Value of $\Delta S_{rxn}^o$ and $\Delta G_{rxn}^o$ has to be calculated for the reaction $3{\text{ C}}_{\text{2}}{\text{H}}_{\text{2}}\left(g\right)\underset{}{\rightleftharpoons }{\text{C}}_{\text{6}}{\text{H}}_{\text{6}}\left(l\right)$. The direction in which the reaction is spontaneous has to be indicated.

Concept Introduction:

Entropy$\left(S\right)$: it is used to describe the disorder. It is the amount of arrangements possible in a system at a particular state.

Value of $\Delta S_{rxn}^o$ can be calculated by the equation:

  $\Delta S_{rxn}^o\text{= }S°\left[\text{products}\right]-S°\left[\text{reactants}\right]$

The Gibbs free energy or the free energy change is a thermodynamic quantity represented by $\Delta G$. Value of $\Delta G_{rxn}^o$ is determined as follows,

  $\Delta G_{rxn}^o=\Delta H_{rxn}^o-T\Delta S_{rxn}^o$

If $\Delta G<0$ then the reaction is spontanous in forward reaction and so the reaction will favor products.

If $\Delta G>0$ then the reaction is spontanous in backward reaction and so the reaction will favor reactants.

If $\Delta G=0$ then the reaction is at equilibrium.