/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 72 The smectic liquid crystalline p... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 11: Problem 72

The smectic liquid crystalline phase can be said to be more highly ordered than the nematic phase. In what sense is this true?

Short Answer

Expert verified
The smectic liquid crystalline phase is more highly ordered than the nematic phase because, in the smectic phase, the rod-like molecules exhibit both parallel orientation and well-defined layered arrangement. In contrast, the nematic phase only displays parallel orientation of rod-like molecules without any layered arrangement, making it less ordered compared to the smectic phase.

Step by step solution

01

Introduction to Liquid Crystal Phases

Liquid crystals are an intermediate state of matter between the solid and liquid phase. They possess properties of both solid and liquid phases. The two main liquid crystal phases we will discuss are the smectic phase and the nematic phase. Both of these phases have a degree of molecular ordering, but the smectic phase is considered to be more highly ordered than the nematic phase.
02

Nematic Phase Ordering

In the nematic phase, the long axes of the rod-like molecules are oriented parallel to one another while maintaining a degree of rotational freedom around their long axis; however, they are not arranged in layers. Due to this orientation, the nematic phase is considered as less ordered than the smectic phase.
03

Smectic Phase Ordering

The smectic phase is characterized by a more organized molecular arrangement compared to the nematic phase. In the smectic phase, the rod-like molecules are not only oriented parallel to each other (similar to the nematic phase) but they also form well-defined layers. This layered arrangement adds an extra level of ordering in the smectic phase, making it more highly ordered compared to the nematic phase.
04

Conclusion

In summary, the smectic liquid crystalline phase is considered to be more highly ordered than the nematic phase because, in the smectic phase, the rod-like molecules are organized both in terms of their orientation and their arrangement in layers. On the other hand, the nematic phase exhibits only parallel orientation of rod-like molecules without any layered arrangement. This extra level of ordering in the smectic phase makes it more highly ordered compared to the nematic phase.

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.

Over 30 million students worldwide already upgrade their learning with 91影视!

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

(a) How does the average kinetic energy of molecules compare with the average energy of attraction between molecules in solids, liquids, and gases? (b) Why does increasing the temperature cause a solid substance to change in succession from a solid to a liquid to a gas? (c) What happens to a gas if you put it under extremely high pressure?

List the three states of matter in order of (a) increasing molecular disorder and (b) increasing intermolecular attraction. (c) Which state of matter is most easily compressed?

Ethyl chloride \(\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}\right)\) boils at \(12^{\circ} \mathrm{C}\) . When liquid \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}\) under pressure is sprayed on a room-temperature \(\left(25^{\circ} \mathrm{C}\right)\) surface in air, the surface is cooled considerably. (a) What does this observation tell us about the specific heat of \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}(g)\) as compared with that of \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}(l) ?\) Assume that the heat lost by the surface is gained by ethyl chloride. What enthalpies must you consider if you were to calculate the final temperature of the surface?

Appendix \(\mathrm{B}\) lists the vapor pressure of water at various external pressures. (a) Plot the data in Appendix B, vaporpressure (torr) versus temperature \(\left(^{\circ} \mathrm{C}\right) .\) From your plot, estimate the vapor pressure of water at body temperature, \(37^{\circ} \mathrm{C}\) (b) Explain the significance of the data point at 760.0 torr, \(100^{\circ} \mathrm{C}\) (c) A city at an altitude of 5000 \(\mathrm{ft}\)above sea level has a barometric pressure of 633 torr. To what temperature would you have to heat water to boil it in this city? (d) A city at an altitude of 500 ft below sea level would have a barometric pressure of 774 torr. To what temperature would you have to heat water to boil it in this city?

Ethylene glycol \(\left(\mathrm{HOCH}_{2} \mathrm{CH}_{2} \mathrm{OH}\right)\) and pentane \(\left(\mathrm{C}_{5} \mathrm{H}_{12}\right)\) are both liquids at room temperature and room pressure, and have about the same molecular weight. (a) One of these liquids is much more viscous than the other. Which one do you predict is more viscous? (b) One of these liquids has a much lower normal boiling point \(\left(36.1^{\circ} \mathrm{C}\right)\) compared to the other one \(\left(198^{\circ} \mathrm{C}\right) .\) Which liquid has the lower normal boiling point? (c) One of these liquids is the major component in antifreeze in automobile engines. Which liquid would you expect to be used as antifreeze? (d) One of these liquids is used as a "blowing agent" in the manufacture of polystyrene foam because it is so volatile. Which liquid would you expect to be used as a blowing agent?
See all solutions

Recommended explanations on Chemistry Textbooks

Organic Chemistry

Read Explanation

Chemical Analysis

Read Explanation

Nuclear Chemistry

Read Explanation

Chemistry Branches

Read Explanation

Making Measurements

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.