Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 9: Problem 51

What is the principal difference between congruent and incongruent phase transformations?

Short Answer

Expert verified
The principal difference between congruent and incongruent phase transformations lies in the change (or lack thereof) in the composition of the substance during the transformation. In a congruent phase transformation, the composition remains the same throughout the transformation process, while in an incongruent phase transformation, the composition changes as the transformation takes place.

Step by step solution

01

Define Congruent Phase Transformation

In a congruent phase transformation, there is no change in the composition of the substance when it transforms from one phase to another. In other words, the chemical composition of the phases involved in the transformation remains the same. Examples of congruent phase transformations include melting and freezing of pure substances like water.
02

Define Incongruent Phase Transformation

In an incongruent phase transformation, there is a change in the composition of the substance as it transforms from one phase to another. As the transformation occurs, the elements or compounds involved in the transition redistribute themselves between the phases, resulting in different chemical compositions. Examples of incongruent phase transformations are the decomposition of limestone (CaCO3) into calcium oxide (CaO) and carbon dioxide (CO2), and the eutectoid transformation in iron-carbon alloys.
03

Principal Difference Between Congruent and Incongruent Phase Transformations

The principal difference between congruent and incongruent phase transformations lies in the change (or lack thereof) in the composition of the substance during the transformation. In a congruent phase transformation, the composition remains the same throughout the transformation process, while in an incongruent phase transformation, the composition changes as the transformation takes place.

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

Compute the mass fraction of eutectoid cementite in an iron-carbon alloy that contains \(0.87 \mathrm{wt} \% \mathrm{C}\).

For a series of \(\mathrm{Fe}-\mathrm{Fe}_{3} \mathrm{C}\) alloys with compositions ranging between \(0.022\) and \(0.76 \mathrm{wt} \% \mathrm{C}\) that have been cooled slowly from \(1000^{\circ} \mathrm{C}\), plot the following: (a) mass fractions of proeutectoid ferrite and pearlite versus carbon concentration at \(725^{\circ} \mathrm{C}\) (b) mass fractions of ferrite and cementite versus carbon concentration at \(725^{\circ} \mathrm{C}\).

For \(5.7 \mathrm{~kg}\) of a magnesium-lead alloy of composition \(50 \mathrm{wt} \% \mathrm{~Pb}-50 \mathrm{wt} \% \mathrm{Mg}\), is it possible, at equilibrium, to have \(\alpha\) and \(\mathrm{Mg}_{2} \mathrm{~Pb}\) phases with respective masses of \(5.13\) and \(0.57 \mathrm{~kg} ?\) If so, what will be the approximate temperature of the alloy? If such an alloy is not possible, then explain why.

Is it possible to have an iron-carbon alloy for which the mass fractions of total cementite and proeutectoid ferrite are \(0.057\) and \(0.36\), respectively? Why or why not?

The mass fraction of eutectoid cementite in an iron-carbon alloy is \(0.109\). On the basis of this information, is it possible to determine the composition of the alloy? If so, what is its composition? If this is not possible, explain why.
See all solutions

Recommended explanations on Physics Textbooks

Scientific Method Physics

Read Explanation

Electrostatics

Read Explanation

Space Physics

Read Explanation

Electricity

Read Explanation

Waves Physics

Read Explanation

Wave Optics

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