Question

Answer Problem 6.14 for a reaction with ${\mathbf{\Delta H}}^{\mathbf{°}}\mathbf{}\mathbf{=}\mathbf{-}\mathbf{20}\mathbf{}\mathbf{kJ}\mathbf{/}\mathbf{mol}$.

Short answer

Answer

1. True.
2. False; ${\mathrm{\Delta G}}^{°}$for the reaction is negative.
3. True.
4. False; The bonds in the starting materials are weaker than the bonds in the product.
5. True.

Step-by-step solution

Step-by-Step SolutionStep 1: Predicting feasibility of a reaction

The feasibility of a reaction (i.e., whether the reaction favors product formation) can be predicted using the ${\mathbf{\Delta H}}^{\mathbf{°}}$and ${\mathbf{\Delta G}}^{\mathbf{°}}$.

A negative value of role="math" localid="1648269334522" ${\mathrm{\Delta H}}^{°}$and ${\mathrm{\Delta G}}^{°}$indicates that the reaction favors the product formation.

Equilibrium constant

Equilibrium constant ( ${\mathbf{K}}_{\mathbf{eq}}$) is determined by the ratio of the amount of products to that of the reactants.

${\mathrm{K}}_{\mathrm{eq}}>1$ signifies that the reaction favors the products.

${\mathrm{K}}_{\mathrm{eq}}<1$signifies that the reaction favors the reactants.

True or False

(a) The reaction is exothermic – True.

The negative value of ${\mathrm{\Delta H}}^{°}$indicates that the reaction is exothermic.

(b)${\mathrm{\Delta G}}^{°}$ for the reaction is positive – False.

Since ${\mathrm{\Delta H}}^{°}$ is directly related to ${\text{ΔG}}^{°}$, the value of ${\text{ΔG}}^{°}$ for the reaction should be negative.

(c) ${\mathrm{K}}_{\mathrm{eq}}$is greater than 1 – True.

Negative value of ${\text{ΔH}}^{°}$ signifies that the products are favored, and in the reactions favoring products the value of the equilibrium constant is always greater than 1.

(d) The bonds in the starting materials are stronger than the bonds in the product – False.

A negative value of ${\mathrm{\Delta H}}^{°}$indicates that the reaction favors the products and therefore the bonds in the starting material should be weaker than the bonds in the product.

(e) The product is favored at equilibrium – True.

The products are favored at equilibrium as $∆{\mathrm{H}}^{°}$ is negative.