Skip to main content
Ch. 20 - Carboxylic Acids
Wade - Organic Chemistry 9th Edition
Wade9th EditionOrganic ChemistryISBN: 9780135213728Non è quello che usi tu?Cambia libro di testo
Capitolo 20, Problema 42c

Peroxyacetic acid (bp = 105 °C) has a lower boiling point than acetic acid (bp = 118 °C), even though peroxyacetic acid has a higher molecular weight. Explain why peroxyacetic acid is more volatile than acetic acid.

Guida verificata passo dopo passo
1
Understand the concept of boiling point: The boiling point of a substance is the temperature at which its vapor pressure equals the atmospheric pressure, allowing it to transition from liquid to gas.
Consider the molecular structure: Acetic acid (CH₃COOH) and peroxyacetic acid (CH₃COOOH) have similar structures, but peroxyacetic acid contains an additional oxygen atom, forming a peroxide linkage.
Analyze intermolecular forces: Acetic acid can form strong hydrogen bonds due to the presence of the hydroxyl group (OH) and the carbonyl group (C=O), which contribute to its higher boiling point.
Evaluate the effect of the peroxide linkage: The peroxide linkage in peroxyacetic acid (O-O bond) is less effective at hydrogen bonding compared to the carbonyl group in acetic acid, resulting in weaker intermolecular forces.
Conclude the volatility: Due to weaker hydrogen bonding in peroxyacetic acid, it has a lower boiling point and is more volatile than acetic acid, despite having a higher molecular weight.

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:
6m

Concetti chiave

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

Hydrogen Bonding

Hydrogen bonding is a strong type of dipole-dipole interaction that occurs when hydrogen is bonded to highly electronegative atoms like oxygen or nitrogen. Acetic acid can form more extensive hydrogen bonds due to its carboxylic acid group, which increases its boiling point compared to peroxyacetic acid, which has a less effective hydrogen bonding capability due to the presence of the peroxide group.
Video consigliato:
00:48
The definition of hydrogenation.

Molecular Structure

The molecular structure of a compound affects its physical properties, including boiling point. Peroxyacetic acid contains a peroxide linkage, which alters its ability to form hydrogen bonds compared to acetic acid. This structural difference results in weaker intermolecular forces in peroxyacetic acid, making it more volatile despite its higher molecular weight.
Video consigliato:
08:41
Review of Molecular Orbitals

Intermolecular Forces

Intermolecular forces, such as hydrogen bonding, dipole-dipole interactions, and van der Waals forces, determine the boiling point of a substance. Acetic acid's stronger hydrogen bonding leads to higher boiling points, while peroxyacetic acid's weaker intermolecular forces due to its peroxide group result in increased volatility and a lower boiling point.
Video consigliato:
03:01
How Van der Waals forces work.
Pratica correlata
Domanda del libro di testo

Draw the mechanism for the last step in the Kiliani-Fischer synthesis.

1091
views
Domanda del libro di testo

Two of the methods for converting alkyl halides to carboxylic acids are covered in Sections 20-8B and 20-8C. One is formation of a Grignard reagent followed by addition of carbon dioxide and then dilute acid. The other is substitution by cyanide ion, followed by hydrolysis of the resulting nitrile. For each of the following conversions, decide whether either or both of these methods would work, and explain why. Show the reactions you would use.

(a)

(b)

1817
views
Domanda del libro di testo

In the presence of a trace of acid, δ-hydroxyvaleric acid forms a cyclic ester (lactone).

(a) Give the structure of the lactone, called δ-valerolactone.

(b) Propose a mechanism for the formation of δ-valerolactone.

1340
views
Domanda del libro di testo

The following NMR spectra correspond to compound of formula (C) C6H10O2. Propose structure, and show how it is consistent with the observed absorptions.

<IMAGE>

3598
views
1
rank
Domanda del libro di testo

Two of the methods for converting alkyl halides to carboxylic acids are covered in Sections 20-8B and 20-8C. One is formation of a Grignard reagent followed by addition of carbon dioxide and then dilute acid. The other is substitution by cyanide ion, followed by hydrolysis of the resulting nitrile. For each of the following conversions, decide whether either or both of these methods would work, and explain why. Show the reactions you would use.

(e)

(f)

590
views
Domanda del libro di testo

The following NMR spectra correspond to compound of formula (A) C9H10O2. Propose structure, and show how it is consistent with the observed absorptions.

<IMAGE>

3777
views
1
rank