Chapter 18.6, Problem 18.9CYU

(a)

Interpretation Introduction

Interpretation:

The ${\text{Δ}}_{\text{r}}{\text{G}}^{\text{°}}$ for the given reaction ${\text{N}}_{\text{2}}\left(\text{g}\right){\text{+O}}_{\text{2}}\left(\text{g}\right)\rightleftarrows \text{2NO}\left(\text{g}\right)$ should be calculated using standard free energies of reactant and product formation and should be identified that whether reaction is reactant or product favoured.

Concept introduction:

The Gibbs free energy or the free energy change is a thermodynamic quantity represented by ${\text{Δ}}_{\text{r}}{\text{G}}^{\text{o}}$. It can be calculated in a similar manner as entropy and enthalpy.  The expression for the free energy change is:

  ${\text{Δ}}_{\text{r}}{\text{G}}^{\text{°}}\text{= }\sum {\text{nΔ}}_{\text{f}}{\text{G}}^{\text{°}}\left(\text{products}\right)\text{- }\sum {\text{nΔ}}_{\text{f}}{\text{G}}^{\text{°}}\left(\text{reactants}\right)$

${\text{Δ}}_{\text{r}}{\text{G}}^{\text{o}}$ gets related to the reaction quotient $\text{Q}$ by the expression ${\text{Δ}}_{\text{r}}{\text{G = Δ}}_{\text{r}}{\text{G}}^{\text{°}}\text{+ RT lnQ}$

For a general reaction, $\text{aA + bB}\to \text{cC + dD}$

  $\text{Q = }\frac{{\left[\text{C}\right]}^{\text{c}}{\left[\text{D}\right]}^{\text{d}}}{{\left[\text{A}\right]}^{\text{a}}{\left[\text{B}\right]}^{\text{b}}}$

(b)

Interpretation Introduction

Interpretation:

The ${\text{Δ}}_{\text{r}}{\text{G}}^{\text{°}}$ for the reaction when $\text{0}\text{.10 atm}{\text{N}}_{\text{2}}\text{,}\text{0}\text{.10}{\text{atm O}}_{\text{2}}\text{and}\text{0}\text{.010}\text{atm NO}$ are mixed should be calculated and should be identified that whether this reaction is spontaneous or not under such given conditions.

Concept introduction:

The Gibbs free energy or the free energy change is a thermodynamic quantity represented by ${\text{Δ}}_{\text{r}}{\text{G}}^{\text{o}}$. It can be calculated in a similar manner as entropy and enthalpy.  The expression for the free energy change is:

  ${\text{Δ}}_{\text{r}}{\text{G}}^{\text{°}}\text{= }\sum {\text{nΔ}}_{\text{f}}{\text{G}}^{\text{°}}\left(\text{products}\right)\text{- }\sum {\text{nΔ}}_{\text{f}}{\text{G}}^{\text{°}}\left(\text{reactants}\right)$

${\text{Δ}}_{\text{r}}{\text{G}}^{\text{o}}$ gets related to the reaction quotient $\text{Q}$ by the expression ${\text{Δ}}_{\text{r}}{\text{G = Δ}}_{\text{r}}{\text{G}}^{\text{°}}\text{+ RT lnQ}$

For a general reaction, $\text{aA + bB}\to \text{cC + dD}$

  $\text{Q = }\frac{{\left[\text{C}\right]}^{\text{c}}{\left[\text{D}\right]}^{\text{d}}}{{\left[\text{A}\right]}^{\text{a}}{\left[\text{B}\right]}^{\text{b}}}$