Gibbs Free Energy - Online Tutor, Practice Problems & Exam Prep

In the given reaction, which direction would be more favored with an increase in temperature?

In the acid-base reaction below, determine the ∆G° in kcal/mol at 279 K.

The equilibrium constant (K_eq) of a reaction can be calculated using the following equation.

• K_eq = e^−∆E/RT

Calculate the equilibrium constant for the following reaction at room temperature (298K).

A. K_eq = 6.0

B. K_eq = 0.006

C. K_eq = 6000

D. K_eq = 6.066

Consider the following equilibrium process and its related ∆G°:

(1) Calculate K_eq.

(2) Determine the % reactants and % products present in an equilibrium mixture at 298 K.

Consider the following reactions A and B:

A:

B:

Determine which reaction will occur more quickly. [Hint: Compare the stability of the bases on the reactant side.]

For T₁ = 40°C and T₂ = 125°C, determine the equilibrium constants and ∆G° if a reaction has ∆H° = 10 kcal/mol and ∆S° = 0.14 kcal/(mol⋅K). How do ∆G° and K_eq change as T increases?

If the value of ΔGº for the following reaction is −2.0 kJ/mol (−0.48 kcal/mol), calculate K_eq at room temperature (25 °C).
CH₃CH₂Br + H₂S ⇌ CH₃CH₂SH + HBr

A. −0.81

B. 0.44

C. 0.81

D. 2.24

If the temperature is increased, which direction of the reaction, if any, would be favored?

In the acid-base reaction below, what is the ∆G° at 380 K?

In the equilibrium (acid-base) reaction below, determine the Gibbs free energy (∆G°) at 289 K.

Determine if the equilibrium constant is going to be greater than, equal to, or less than 1 for the following equilibrium reaction. Justify your answer.

Consider the equilibrium process shown below and its corresponding ∆G°:

(1) What is the equilibrium constant (K_eq) of the reaction?

(2) Calculate the % reactants and % products in an equilibrium mixture at 298 K.

1. Which of the following reactions has a greater equilibrium constant?

2. A student starts both reactions with a reactant concentration of 1.0 M. Determine which reaction produces the most product after the reactions have reached equilibrium.

The value of ΔG° for the reaction below is −8.20 kJ/mol (−1.96 kcal/mol).

CH₃Cl + H₂S ⇌ CH₃SH + HCl

At 25.0°C, the initial concentrations of CH ₃Cl and H₂S are both 1.00 M. Determine the equilibrium concentrations of all species.

Consider the following reaction of propan-2-ol and chloroethane:

This reaction occurs through the following mechanism:

Explain why this reaction mechanism is favored and estimate the value of K _eq based on the stability of the anions.

Is the equilibrium constant going to be greater than, equal to, or less than 1 for the following equilibrium reaction? Explain.

Determine the probable transition state of the given reaction. Make sure to indicate which bond is broken or formed.

What is the probable transition state of the given reaction? Make sure to indicate which bond is broken or formed.

Predict the probable transition state of the given reaction. Make sure to show which bond is broken or formed.

At 25 °C, what is the ∆G° for the conversion of "axial" isopropylcylcohexane to "equatorial" isopropylcylcohexane?

At equilibrium, what percentage of ethylcyclohexane has its ethyl substituent in an equatorial position? (ΔG° for the conversion of equatorial ethylcyclohexane to axial ethylcyclohexane at 25°C is −1.81 kcal/mol)

When used as local anesthetics, it takes a longer time for one-half of etidocaine to be metabolized than tetracaine. Explain why. 

The intramolecular reaction of the cis alkene (Reaction A) is relatively faster than the intermolecular reaction (Reaction B). Suppose a trans alkene undergoes a similar reaction. Which of the two reactions will its rate be similar?

Reaction A

Reaction B

If reactant X and product Y are in equilibrium, determine the relative amounts of X and Y present at 30°C when (i) ∆G° = 4.76 kcal and (ii) ∆G° = 0.78 kcal.

If reactant X and product Y are in equilibrium, what are the relative amounts of X and Y present at 27°C when (i) ∆G° = −4.60 kcal and (ii) ∆G° = −0.97 kcal?

At 28.9°C, the reaction between a certain alkyl halide and the ⁻OH has a ΔG° value of −24.9 kcal/mol. Determine the reaction's equilibrium constant (K_eq).

Which properties are affected when a reaction is performed with a catalyst compared to the same reaction without a catalyst?

∆G°, ∆H^‡, E_a, ∆S^‡, ∆H°, K_eq, ∆G^‡, ∆S°, k

In the presence of a base, two molecules of pentan-3-one can condense to form a hydroxy ketone. Assuming that pentan-3-one has an initial concentration of 1.00 M and that about 10.0% of pentan-3-one is converted to the hydroxy ketone product at room temperature, estimate the value of ΔG°.