Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 11: Problem 22

Why is the molar enthalpy of vaporization of a substance much higher than the molar enthalpy of fusion?

Short Answer

Expert verified
The molar enthalpy of vaporization for a substance is significantly higher than the molar enthalpy of fusion due to the higher energy requirement to overcome all the intermolecular attractions and transition from a liquid to a gaseous state, creating a high level of disorder.

Step by step solution

01

Definition of Molar Enthalpy of Fusion

The molar enthalpy of fusion refers to the amount of energy necessary, per mole of the substance, to change the substance from a solid to a liquid state at its melting point under standard conditions.
02

Definition of Molar Enthalpy of Vaporization

The molar enthalpy of vaporization is the quantity of energy required, per mole of the substance, to change the substance from a liquid to a gaseous state at its boiling point under standard options. This transition to the gaseous state involves breaking intermolecular attractions in the liquid, making the molecules disordered.
03

Contrast between Molar Enthalpy of Fusion and Vaporization

In the case of molar enthalpy of fusion, some intermolecular attractions must be broken to permit a slight increase in disorder (from rigid lattice in solid to a bit more randomness in liquid). However, to achieve vaporization, much more energy is needed to overcome the entirety of the intermolecular attractions, as this process leads to a very high increase in disorder (from close contact in liquid to complete freedom in gas). This results in the vaporization's molar enthalpy being higher than fusion's.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

What is a triple point?

The molar enthalpy of fusion of water is 6.009 \(\mathrm{kJ} / \mathrm{mol}\) at \(0^{\circ} \mathrm{C}\) . Explain what this statement means.

How does a pressure cooker work?

The critical point for carbon tetrachloride is at \(283^{\circ} \mathrm{C}\) and \(4.5 \times 10^{3}\) kPa. The triple point is at \(-87.0^{\circ} \mathrm{C}\) and 28.9 \(\mathrm{kPa}\) . The normal boiling point is \(76.7^{\circ} \mathrm{C}\) . Sketch the phase diagram.

What is surface tension?
See all solutions

Recommended explanations on Chemistry Textbooks

Inorganic Chemistry

Read Explanation

Chemistry Branches

Read Explanation

Organic Chemistry

Read Explanation

Chemical Analysis

Read Explanation

The Earths Atmosphere

Read Explanation

Physical Chemistry

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free