/*! 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 69 For a given substance, the liqui... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 11: Problem 69

For a given substance, the liquid crystalline phase tends to be more viscous than the liquid phase. Why?

Short Answer

Expert verified
The liquid crystalline phase tends to be more viscous than the liquid phase because of the increased molecular order in the liquid crystalline phase. In this phase, the molecules exhibit some degree of long-range order, typically forming layered or aligned structures, which restricts their freedom of movement and makes it harder for them to slide past each other. This results in stronger intermolecular forces and reduced mobility, leading to higher viscosity compared to the liquid phase, where molecules are randomly arranged and can easily slide past one another.

Step by step solution

01

Definition of Liquid and Liquid Crystalline Phase

A liquid is a state of matter characterized by its ability to flow and adapt to the shape of its container, with short-range molecular order but no long-range order. On the other hand, a liquid crystalline phase is an intermediate phase between a liquid and a crystal, where the molecules exhibit some degree of long-range order while still maintaining fluidity.
02

Definition of Viscosity

Viscosity (\(\eta\)) is a measure of a fluid's resistance to flow, or deformation by shear stress or tensile stress. It refers to the internal friction between adjacent layers of fluid that are moving at different velocities. Higher viscosity means that a fluid has more resistance to flow and appears thicker. Conversely, lower viscosity indicates a thinner fluid that flows more easily.
03

Molecular Structure in Liquid and Liquid Crystalline Phase

In the liquid phase, the molecules are randomly arranged and can easily slide past one another, which allows the liquid to flow easily. In the liquid crystalline phase, the molecules are more ordered, typically forming layered or aligned structures. These ordered structures reduce the freedom of movement of the molecules, making it harder for them to slide past each other.
04

Comparing Viscosity in Liquid and Liquid Crystalline Phase

Due to the increased molecular order in the liquid crystalline phase, the molecules experience more resistance to flow. This results in a higher viscosity in the liquid crystalline phase compared to the liquid phase. The ordered molecular arrangements in the liquid crystalline phase create stronger intermolecular forces and reduce the mobility of the molecules, thus increasing the viscosity.

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

True or false: (a) For molecules with similar molecular weights, the dispersion forces become stronger as the molecules become more polarizable. (b) For the noble gases the dispersion forces decrease while the boiling points increase as you go down the column in the periodic table. (c) In terms of the total attractive forces for a given substance, dipole- dipole interactions, when present, are always greater than dispersion forces.( \(\mathbf{d}\) ) All other factors being the same, dispersion forces between linear molecules are greater than those between molecules whose shapes are nearly spherical. (e) The larger the atom, the more polarizable it is.

The boiling points, surface tensions, and viscosities of water and several alcohols are as shown below:(a) From ethanol to propanol to \(n\) -butanol the boiling points, surface tensions, and viscosities all increase. What is the reason for this increase? (b) How do you explain the fact that propanol and ethylene glycol have similar molecular weights (60 versus 62 amu), yet the viscosity of ethylene glycol is more than 10 times larger than propanol? (c) How do you explain the fact that water has the highest surface tension but the lowest viscosity?

(a) Which type of intermolecular attractive force operates between all molecules? (b) Which type of intermolecular attractive force operates only between polar molecules? (c) Which type of intermolecular attractive force operates only between the hydrogen atom of a polar bond and a nearby small electronegative atom?

A watch with a liquid crystal display (LCD) does not function properly when it is exposed to low temperatures during a trip to Antarctica. Explain why the LCD might not function well at low temperature.

Butane and 2 -methylpropane, whose space-filling models are shown here, are both nonpolar and have the same molecular formula, \(\mathrm{C}_{4} \mathrm{H}_{10},\) yet butane has the higher boiling point \(\left(-0.5^{\circ} \mathrm{C}\) compared to \(-11.7^{\circ} \mathrm{C}\right) .\) Explain.
See all solutions

Recommended explanations on Chemistry Textbooks

Organic Chemistry

Read Explanation

Nuclear Chemistry

Read Explanation

The Earths Atmosphere

Read Explanation

Chemical Analysis

Read Explanation

Kinetics

Read Explanation

Chemical Reactions

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.