Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 18: Problem 41

Give a detailed example of each of the following, with an explanation: (a) a thermodynamically spontaneous process; (b) a process that would violate the first law of thermodynamics; (c) a process that would violate the second law of thermodynamics; (d) an irreversible process; (e) an equilibrium process.

Short Answer

Expert verified
Examples: a) A thermodynamically spontaneous process: Melting of ice at room temperature. b) A process violating the first law of thermodynamics: Concept of a 'Perpetual motion machine'. c) A process violating the second law of thermodynamics: Cold coffee reheating itself to room temperature. d) An irreversible process: Burning a piece of paper. e) An equilibrium process: A glass of saturated salt water kept undisturbed at constant temperature and pressure.

Step by step solution

01

Identifying a Thermodynamically Spontaneous Process

A thermodynamically spontaneous process is one that can occur without any external energy input. A natural and common example is the melting of ice at room temperature. This process is spontaneous because given enough time, the ice at a temperature below 0°C will absorb energy from the environment and transform into water, without any outside interference.
02

Identifying a Process that Violates the First Law of Thermodynamics

The First Law of Thermodynamics states that energy can neither be created nor destroyed, only transferred or changed in form. Thus, any process claiming to create or destroy energy would violate this law. A 'perpetual motion machine' is a hypothetical example, as it claims to work indefinitely without an energy source, implying that it creates its own energy, which is in direct violation of the First Law.
03

Identifying a Process that Violates the Second Law of Thermodynamics

The Second Law of Thermodynamics states that the entropy of an isolated system can never decrease over time. It is essentially a statement about the natural direction of heat flow from hot to cold. A cold object warming itself without any heat source, such as a cold cup of coffee reheating itself to room temperature, is a process that would violate the Second Law.
04

Identifying an Irreversible Process

An irreversible process is one that cannot return to its original state without inducing some change in the surroundings. Burning a piece of paper is an example. Once the paper is burnt, it cannot return to its original form.
05

Identifying an Equilibrium Process

An equilibrium process is one in which the system is at equilibrium at every stage of the process. The process proceeds infinitesimally slow so that the system composition remains uniform throughout the process. A glass of saturated salt water left undisturbed at a constant temperature and pressure is an example. In this state, the rate of salt dissolving is equal to the rate of salt precipitating from the solution, so we can consider the system to be in equilibrium.

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

In the Mond process for the purification of nickel, carbon monoxide is reacted with heated nickel to produce \(\mathrm{Ni}(\mathrm{CO})_{4},\) which is a gas and can therefore be separated from solid impurities: $$ \mathrm{Ni}(s)+4 \mathrm{CO}(g) \rightleftharpoons \mathrm{Ni}(\mathrm{CO})_{4}(g) $$ Given that the standard free energies of formation of \(\mathrm{CO}(g)\) and \(\mathrm{Ni}(\mathrm{CO})_{4}(g)\) are \(-137.3 \mathrm{~kJ} / \mathrm{mol}\) and \(-587.4 \mathrm{~kJ} / \mathrm{mol}\), respectively, calculate the equilibrium constant of the reaction at \(80^{\circ} \mathrm{C}\). Assume that \(\Delta G_{f}^{\circ}\) is temperature independent.

The equilibrium constant \(K_{P}\) for the reaction $$ \mathrm{CO}(g)+\mathrm{Cl}_{2}(g) \rightleftharpoons \mathrm{COCl}_{2}(g) $$ is \(5.62 \times 10^{35}\) at \(25^{\circ} \mathrm{C}\). Calculate \(\Delta G_{\mathrm{f}}^{\circ}\) for \(\mathrm{COCl}_{2}\) at \(25^{\circ} \mathrm{C}\).

A student placed \(1 \mathrm{~g}\) of each of three compounds \(\mathrm{A}\) \(\mathrm{B},\) and \(\mathrm{C}\) in a container and found that after 1 week no change had occurred. Offer some possible explanations for the fact that no reactions took place. Assume that \(\mathrm{A}, \mathrm{B},\) and \(\mathrm{C}\) are totally miscible liquids.

(a) Calculate \(\Delta G^{\circ}\) and \(K_{P}\) for the following equilibrium reaction at \(25^{\circ} \mathrm{C}\). The \(\Delta G_{f}^{\circ}\) values are 0 for \(\mathrm{Cl}_{2}(g),-286 \mathrm{~kJ} / \mathrm{mol}\) for \(\mathrm{PCl}_{3}(g),\) and \(-325 \mathrm{~kJ} / \mathrm{mol}\) for \(\mathrm{PCl}_{5}(g)\) $$ \mathrm{PCl}_{5}(g) \rightleftharpoons \mathrm{PCl}_{3}(g)+\mathrm{Cl}_{2}(g) $$. (b) Calculate \(\Delta G\) for the reaction if the partial pressures of the initial mixture are \(P_{\mathrm{PCl}_{5}}=0.0029 \mathrm{~atm}\) \(P_{\mathrm{PCl}_{3}}=0.27 \mathrm{~atm},\) and \(P_{\mathrm{Cl}_{2}}=0.40 \mathrm{~atm}\).

The molar heat of vaporization of ethanol is \(39.3 \mathrm{~kJ} / \mathrm{mol}\) and the boiling point of ethanol is \(78.3^{\circ} \mathrm{C}\) Calculate \(\Delta S\) for the vaporization of \(0.50 \mathrm{~mol}\) ethanol.
See all solutions

Recommended explanations on Chemistry Textbooks

Kinetics

Read Explanation

Physical Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Inorganic Chemistry

Read Explanation

Chemistry Branches

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