Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 11: Problem 40

Name the phase transition in each of the following situations and indicate whether it is exothermic or endothermic: (a) Iodine solid turns to iodine gas when it is heated. (b) Snowflakes turn into water when they fall on an open palm. (c) Droplets of water appear on grass in a cold humid morning. (d) Dry ice gradually disappears when left at room temperature for some period of time.

Short Answer

Expert verified
(a) Sublimation, Endothermic; (b) Melting, Endothermic; (c) Condensation, Exothermic; (d) Sublimation, Endothermic

Step by step solution

01

Situation (a) - Iodine Solid to Iodine Gas

In this situation, iodine is turning from a solid directly to a gas when heated. This phase transition is called sublimation. Since heat is being absorbed during this process to turn the solid into a gas, it is an endothermic process. So, the phase transition for (a) is Sublimation, and it is Endothermic.
02

Situation (b) - Snowflakes Turns into Water

In this case, snowflakes are changing from a solid-state (ice) to a liquid state (water) when they fall on an open palm. This phase transition is called melting or fusion. Snowflakes absorb heat from the palm to turn into water, making this an endothermic process. So, the phase transition for (b) is Melting, and it is Endothermic.
03

Situation (c) - Droplets of Water Appear on Grass

In this situation, we see water droplets forming on grass in a cold humid morning. This means the water vapor in the air (gas state) is turning into a liquid state (water droplets) when it cools down. This phase transition is called condensation. As the water vapor releases heat to turn into liquid water, it is an exothermic process. So, the phase transition for (c) is Condensation, and it is Exothermic.
04

Situation (d) - Dry Ice Disappears

In this situation, dry ice (solid-state) gradually disappears when left at room temperature for some period. This means it is turning from a solid-state directly to a gas state (CO2 gas). This phase transition is also called sublimation. During this process, dry ice absorbs heat from the surroundings to turn into CO2 gas, making this an endothermic process. So, the phase transition for (d) is Sublimation, and it is Endothermic.

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

\(\mathrm{CHClF}_{2}\) is a type of hydrochlorofluorocarbon (HCFC) that has a comparatively lower damaging effect on the ozone layer. It is used as a replacement for chlorofluorocarbons (CFCs). The heat of vaporization is \(233.95 \mathrm{~kJ} / \mathrm{g}\). What mass of this substance must evaporate to freeze \(15 \mathrm{~g}\) of water initially at \(15^{\circ} \mathrm{C}\) ? (The heat of fusion of water is \(334 \mathrm{~J} / \mathrm{g} ;\) the specific heat of water is \(4.18 \mathrm{~J} / \mathrm{g} \cdot \mathrm{K} .\) )

Rationalize the difference in boiling points in each pair: (a) $\left(\mathrm{CH}_{3}\right)_{2} \mathrm{O}\left(-23^{\circ} \mathrm{C}\right)\( and \)\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH} \quad\left(78^{\circ} \mathrm{C}\right),$ (b) \(\mathrm{CO}_{2}\left(-78.5^{\circ} \mathrm{C}\right)\) and $\mathrm{CS}_{2}\left(46.2^{\circ} \mathrm{C}\right),(\mathbf{c}) \mathrm{CH}_{3} \mathrm{COCH}_{3}\left(50.5^{\circ} \mathrm{C}\right)$ and \(\mathrm{CH}_{3} \mathrm{COOH}\left(101^{\circ} \mathrm{C}\right)\)

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 \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}(l) ?(\mathbf{b})\) 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?

(a) What is the significance of the critical point in a phase diagram? (b) Why does the line that separates the gas and liquid phases end at the critical point?

(a) Two pans of water are on different burners of a stove. One pan of water is boiling vigorously, while the other is boiling gently. What can be said about the temperature of the water in the two pans? (b) A large container of water and a small one are at the same temperature. What can be said about the relative vapor pressures of the water in the two containers?
See all solutions

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Read Explanation

Chemistry Branches

Read Explanation

Organic Chemistry

Read Explanation

Inorganic Chemistry

Read Explanation

Kinetics

Read Explanation

Nuclear 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