Skip to main content
Ch.12 - Liquids, Solids & Intermolecular Forces
Tro - Chemistry: A Molecular Approach 5th Edition
Tro5th EditionChemistry: A Molecular ApproachISBN: 9780134874371Non è quello che usi tu?Cambia libro di testo
Capitolo 12, Problema 44b

In each pair of compounds, pick the one with the higher vapor pressure at a given temperature. Explain your reasoning. b. CH3CH2CH2OH or CH3OH

Guida verificata passo dopo passo
1
Step 1: Understand that vapor pressure is a measure of the tendency of a substance to transition into the gas phase. It is influenced by the strength of the intermolecular forces within the substance. The weaker the intermolecular forces, the higher the vapor pressure.
Step 2: Identify the types of intermolecular forces in each compound. Both CH3CH2CH2OH (propanol) and CH3OH (methanol) are alcohols, and thus have hydrogen bonding, dipole-dipole interactions, and London dispersion forces.
Step 3: Compare the strength of the intermolecular forces in each compound. Both compounds have similar types of intermolecular forces, but propanol has a longer carbon chain, which increases the strength of its London dispersion forces.
Step 4: Recall that substances with stronger intermolecular forces have lower vapor pressures. Therefore, methanol, with its shorter carbon chain and weaker London dispersion forces, will have a higher vapor pressure than propanol.
Step 5: Conclude that CH3OH (methanol) has a higher vapor pressure at a given temperature than CH3CH2CH2OH (propanol) due to its weaker intermolecular forces.

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:
1m

Concetti chiave

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

Vapor Pressure

Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid or solid phase at a given temperature. It reflects the tendency of molecules to escape from the liquid phase into the gas phase. Compounds with weaker intermolecular forces generally exhibit higher vapor pressures because their molecules can more easily enter the vapor phase.
Video consigliato:
Percorso guidato
02:40
Raoult's Law and Vapor Pressure

Intermolecular Forces

Intermolecular forces are the forces of attraction or repulsion between neighboring particles (atoms, molecules, or ions). These forces include hydrogen bonding, dipole-dipole interactions, and London dispersion forces. Stronger intermolecular forces result in lower vapor pressures, as more energy is required for molecules to escape into the vapor phase.
Video consigliato:
Percorso guidato
01:59
Intermolecular vs Intramolecular Forces

Hydrogen Bonding

Hydrogen bonding is a specific type of strong dipole-dipole interaction that occurs when hydrogen is bonded to highly electronegative atoms like oxygen, nitrogen, or fluorine. In the context of alcohols, such as CH3CH2CH2OH and CH3OH, hydrogen bonding significantly influences their physical properties, including vapor pressure. The presence of more hydrogen bonds typically leads to lower vapor pressure due to the increased energy required to break these interactions.
Video consigliato:
Percorso guidato
01:22
Hydrogenation Reactions