Skip to main content
Ch. 5 - Chemical Reaction Analysis: Thermodynamics and Kinetics
Mullins - Organic Chemistry: A Learner Centered Approach 1st Edition
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Non è quello che usi tu?Cambia libro di testo
Tutti i libri di testoMullins 1st EditionCh. 5 - Chemical Reaction Analysis: Thermodynamics and KineticsProblema 25c
Capitolo 4, Problema 25c

Calculate ∆G°, ∆H°, and ∆S° for the following acid–base reactions. Rationalize the value of ∆H° based on the structure of the conjugate bases. [Assume T = 298 K.]
(c) Chemical equation showing the reaction between hydronium ion and bromide ion to form water and hydrobromic acid.

Guida verificata passo dopo passo
1
Step 1: Begin by identifying the acid and base in the given reaction. Write the chemical equation for the acid-base reaction, including the conjugate acid and conjugate base formed.
Step 2: Use the relationship between Gibbs free energy (∆G°), enthalpy (∆H°), and entropy (∆S°) given by the equation: ∆G=∆H-T∆S. Rearrange this equation to solve for any missing variable if needed.
Step 3: To calculate ∆G°, use the equilibrium constant (K) for the reaction and the equation: ∆G=-RTlnK, where R is the gas constant (8.314 J/mol·K) and T is the temperature in Kelvin (298 K).
Step 4: Rationalize the value of ∆H° by analyzing the structure of the conjugate bases. Consider factors such as resonance stabilization, electronegativity, and bond strength in the conjugate bases to explain why the enthalpy change occurs.
Step 5: Calculate ∆S° using the relationship ∆S=(∆H-∆G)/T. Ensure all values are in consistent units (e.g., J or kJ) before performing the calculation.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
9m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Gibbs Free Energy (∆G°)

Gibbs Free Energy (∆G°) is a thermodynamic potential that measures the maximum reversible work obtainable from a thermodynamic system at constant temperature and pressure. It is crucial for predicting the spontaneity of a reaction; a negative ∆G° indicates a spontaneous process, while a positive value suggests non-spontaneity. The relationship between ∆G°, enthalpy (∆H°), and entropy (∆S°) is given by the equation ∆G° = ∆H° - T∆S°, where T is the temperature in Kelvin.
Video consigliato:
05:02
Breaking down the different terms of the Gibbs Free Energy equation.

Enthalpy (∆H°)

Enthalpy (∆H°) is a measure of the total heat content of a system and reflects the energy changes during a chemical reaction. It can be either exothermic (releasing heat, ∆H° < 0) or endothermic (absorbing heat, ∆H° > 0). The value of ∆H° can be rationalized by examining the stability and structure of the reactants and products, particularly the strength of bonds broken and formed, which influences the overall energy change.
Video consigliato:
04:38
Calculating Enthalpies

Entropy (∆S°)

Entropy (∆S°) is a measure of the disorder or randomness in a system. In chemical reactions, an increase in entropy (∆S° > 0) typically favors spontaneity, as systems tend to evolve towards greater disorder. The change in entropy can be influenced by factors such as the number of molecules, phase changes, and the complexity of the molecular structures involved in the reaction, which are essential for understanding the thermodynamic favorability of acid-base reactions.
Video consigliato:
02:46
Explaining what entropy is.
Pratica correlata
Domanda del libro di testo

Calculate ∆G°, ∆H°, and ∆S° for the following acid–base reactions. Rationalize the value of ∆H° based on the structure of the conjugate bases. [Assume T = 298 K.]

(b)

931
views
Domanda del libro di testo

For the following acid–base reaction, (f) calculate ∆G° at 373 K.

1129
views
Domanda del libro di testo

Calculate ∆G°, ∆H°, and ∆S° for the following acid–base reactions. Rationalize the value of ∆H° based on the structure of the conjugate bases. [Assume T = 298 K.]

(a)

1133
views
Domanda del libro di testo

For the reaction coordinate diagram shown, is the forward or reverse reaction faster?

1632
views
Domanda del libro di testo

Within the following pairs, pick which reaction you would expect to be faster based on having a higher value of the frequency factor (A).

(a)

1141
views
Domanda del libro di testo

Within the following pairs, pick which reaction you would expect to be faster based on having a higher value of the frequency factor (A).

(b)

774
views