Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 12: Problem 12

Surface tension, viscosity, and vapor pressure are all related to intermolecular forces. Why do surface tension and viscosity decrease with temperature, whereas vapor pressure increases with temperature?

Short Answer

Expert verified
Surface tension and viscosity decrease with temperature because higher temperature means higher kinetic energy of particles which allows them to overcome the attractive intermolecular forces more easily, reducing the resistance to flow (surface tension and viscosity). Vapor pressure increases with temperature because higher temperature (kinetic energy) provides more molecules with the energy needed to escape from the liquid's surface and become a gas, which effectively increases the rate of evaporation (vapor pressure).

Step by step solution

01

Explanation of Surface Tension and Viscosity

Surface tension and viscosity are measures of the extent to which a liquid resists flow. Both of these properties result from the attractive intermolecular forces within the liquid. So, if the temperature increases, the kinetic energy of the particles also increases, they move more rapidly and can overcome the attractive forces more easily leading to a decrease in both surface tension and viscosity.
02

Explanation of Vapor Pressure

Vapor pressure is a measure of a liquid's evaporation rate. When temperature increases, the kinetic energy of the particles also increases which translates to more molecules moving fast enough to escape from the liquid’s surface and become a gas, thus increasing the vapor pressure.

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

The following data are given for \(\mathrm{CCl}_{4}\). Normal melting point, \(-23^{\circ} \mathrm{C} ;\) normal boiling point, \(77^{\circ} \mathrm{C} ;\) density of liquid \(1.59 \mathrm{g} / \mathrm{mL} ; \Delta H_{\text {fus }}=3.28 \mathrm{kJ} \mathrm{mol}^{-1} ;\) vapor pressure at \(25^{\circ} \mathrm{C}, 110\) Torr. (a) What phases-solid, liquid, and/or gas-are present if \(3.50 \mathrm{g} \mathrm{CCl}_{4}\) is placed in a closed \(8.21 \mathrm{L}\) container at \(25^{\circ} \mathrm{C} ?\) (b) How much heat is required to vaporize 2.00 L of \(\mathrm{CCl}_{4}(\mathrm{l})\) at its normal boiling point?

Because solid \(p\) -dichlorobenzene, \(\mathrm{C}_{6} \mathrm{H}_{4} \mathrm{Cl}_{2},\) sublimes rather easily, it has been used as a moth repellent. From the data given, estimate the sublimation pressure of \(\mathrm{C}_{6} \mathrm{H}_{4} \mathrm{Cl}_{2}(\mathrm{s})\) at \(25^{\circ} \mathrm{C} .\) For \(\mathrm{C}_{6} \mathrm{H}_{4} \mathrm{Cl}_{2} ; \mathrm{mp}=\) \(53.1^{\circ} \mathrm{C} ;\) vapor pressure of \(\mathrm{C}_{6} \mathrm{H}_{4} \mathrm{Cl}_{2}(1)\) at \(54.8^{\circ} \mathrm{C}\) is \(10.0 \mathrm{mmHg} ; \Delta H_{\text {fus }}=17.88 \mathrm{kJ} \mathrm{mol}^{-1} ; \Delta H_{\text {vap }}=\) \(72.22 \mathrm{k}] \mathrm{mol}^{-1}\)

Sketch a plausible phase diagram for hydrazine \(\left(\mathrm{N}_{2} \mathrm{H}_{4}\right)\) from the following data: triple point \(\left(2.0^{\circ} \mathrm{C}\right)\) and \(3.4 \mathrm{mm} \mathrm{Hg}\) ), the normal melting point \(\left(2^{\circ} \mathrm{C}\right),\) the normal boiling point \(\left(113.5^{\circ} \mathrm{C}\right),\) and the critical point \(\left(380^{\circ} \mathrm{C} \text { and } 145 \mathrm{atm}\right) .\) The density of the liquid is less than that of the solid. Label significant data points on this diagram. Are there any features of the diagram that remain uncertain? Explain.

A 7.53 I. sample of \(\mathrm{N}_{2}(\mathrm{g})\) at \(742 \mathrm{mmHg}\) and \(45.0^{\circ} \mathrm{C}\) is bubbled through \(\mathrm{CCl}_{4}(1)\) at \(45.0^{\circ} \mathrm{C} .\) Assuming the gas becomes saturated with \(\mathrm{CCl}_{4}(\mathrm{g}),\) what is the volume of the resulting gaseous mixture, if the total pressure remains at \(742 \mathrm{mm} \mathrm{Hg}\) and the temperature remains at \(45^{\circ} \mathrm{C} ?\) The vapor pressure of \(\mathrm{CCl}_{4}\) at \(45^{\circ} \mathrm{C}\) is \(261 \mathrm{mmHg}\)

How many liters of \(\mathrm{CH}_{4}(\mathrm{g}),\) measured at \(23.4^{\circ} \mathrm{C}\) and \(768 \mathrm{mmHg},\) must be burned to provide the heat needed to vaporize 3.78 L of water at \(100^{\circ} \mathrm{C}\) ? \(\Delta \mathrm{H}_{\text {combustion }}=\) \(-8.90 \times 10^{2} \mathrm{kJmol}^{-1} \mathrm{CH}_{4} \quad\) For \(\quad \mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \quad\) at \(\quad 100^{\circ} \mathrm{C}\) \(d=0.958 \mathrm{g} \mathrm{cm}^{-3},\) and \(\Delta H_{\mathrm{vap}}=40.7 \mathrm{kJmol}^{-1}\)
See all solutions

Recommended explanations on Chemistry Textbooks

Nuclear Chemistry

Read Explanation

Making Measurements

Read Explanation

The Earths Atmosphere

Read Explanation

Physical Chemistry

Read Explanation

Kinetics

Read Explanation

Organic 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