Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 11: Problem 70

How do the boiling points and melting points of water and carbon tetrachloride vary with pressure? Explain any difference in behavior of these two substances.

Short Answer

Expert verified
The boiling point of water and carbon tetrachloride generally increase with pressure. However, when it comes to melting points, water's melting point decreases with an increase in pressure due to its anomalous expansion while the melting point of carbon tetrachloride increases with an increase in pressure.

Step by step solution

01

Understanding the effect of pressure on boiling point

Typically, the boiling point of a substance increases as the pressure increases. That’s because increased pressure makes it harder for the molecules to escape from the liquid phase into the gas phase. Boiling is when this escape happens all through the liquid and not just on the surface (that’s evaporation). So for water, raising the pressure will raise the boiling point, while reducing pressure will reduce the boiling point.
02

Comparing with carbon tetrachloride

For carbon tetrachloride, the boiling point also increases with pressure. However, this compound behaves differently than water when it comes to its phase diagram. The main difference occurs in the solid-liquid phase boundary, where for water this boundary has a positive slope, while for carbon tetrachloride, this boundary has a negative slope in the phase diagram.
03

Understanding the effect of pressure on melting point

In general, increasing pressure increases the melting point of a substance because it makes it harder for the molecules to move from the more orderly solid phase to the less orderly liquid phase. When pressure is increased on ice (solid water), its melting point decreases. This is unusual, and is due to the fact that ice is less dense than liquid water and occupies more volume. However, for substances like carbon tetrachloride, where the solid form is denser than the liquid, increasing pressure increases the melting point.

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 molar heats of fusion and sublimation of molecular iodine are \(15.27 \mathrm{~kJ} / \mathrm{mol}\) and \(62.30 \mathrm{~kJ} / \mathrm{mol}\), respectively. Estimate the molar heat of vaporization of liquid iodine.

A student is given four solid samples labeled \(W, X, Y\), and \(Z\). All except \(Z\) have a metallic luster. She is told that the solids could be gold, lead sulfide, quartz \(\left(\mathrm{SiO}_{2}\right),\) and iodine. The results of her investigations are as follows: (a) \(\mathrm{W}\) is a good electrical conductor; \(\mathrm{X}\), \(\mathrm{Y},\) and \(\mathrm{Z}\) are poor electrical conductors. (b) When the solids are hit with a hammer, W flattens out, X shatters into many pieces, \(Y\) is smashed into a powder, and \(Z\) is cracked. (c) When the solids are heated with a Bunsen burner, Y melts with some sublimation, but \(\mathrm{X}, \mathrm{W},\) and \(\mathrm{Z}\) do not melt. (d) In treatment with \(6 \mathrm{M}\) \(\mathrm{HNO}_{3}, \mathrm{X}\) dissolves; there is no effect on \(\mathrm{W}, \mathrm{Y},\) or \(\mathrm{Z}\) On the basis of these test results, identify the solids.

Define the following terms: crystalline solid, lattice point, unit cell, coordination number, closest packing.

A pressure cooker is a sealed container that allows steam to escape when it exceeds a predetermined pressure. How does this device reduce the time needed for cooking?

A \(\mathrm{CO}_{2}\) fire extinguisher is located on the outside of a building in Massachusetts. During the winter months, one can hear a sloshing sound when the extinguisher is gently shaken. In the summertime there is often no sound when it is shaken. Explain. Assume that the extinguisher has no leaks and that it has not been used.
See all solutions

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Read Explanation

Physical Chemistry

Read Explanation

Chemistry Branches

Read Explanation

Inorganic Chemistry

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.

Sign-up for free