Chapter 21, Problem 24PS

Chemistry & Chemical Reactivity

10th Edition
John C. Kotz + 3 others
ISBN: 9781337399074

Chapter
Section

Chemistry & Chemical Reactivity

10th Edition
John C. Kotz + 3 others
ISBN: 9781337399074
Textbook Problem

Using data in Appendix L, calculate ΔrH°, ΔrG°, and ΔrS° for the reaction of carbon and water to give CO and H2 at 298 K.

Interpretation Introduction

Interpretation:

To determine the ΔrH°,ΔrG° and ΔrS° for the production of hydrogen by reaction of carbon and water.

Concept introduction:

The Gibbs free energy or the free energy change is a thermodynamic quantity represented by ΔrG. The expression for the free energy change is:

ΔrG°=nΔfG°(products)nΔfG°(reactants)

The expression for the enthalpy change is:

ΔrH°=nΔfH°(products)nΔfH°(reactants)

The expression for the entropy change is:

ΔrS°=nS°(products)nS°(reactants)

Explanation

The Î”rGÂ°,Î”rHÂ° and Î”rSÂ° for the given reaction is calculated below.

Given:

Refer to Appendix L for the values of standard free energy values.

The given reaction is,

â€‚Â C(s)Â +Â H2O(g)â‡„CO(g)+H2(g)

The Î”rGÂ° for C(s) is 0Â kJ/mol.

The Î”rGÂ° for H2O(g) is âˆ’228.59Â kJ/mol.

The Î”rGÂ° for CO(g) is âˆ’137.168Â kJ/mol.

The Î”rGÂ° for H2(g) is 0Â kJ/mol.

The expression for the free energy change is:

Î”rGÂ°=âˆ‘nÎ”fGÂ°(products)âˆ’âˆ‘nÎ”fGÂ°(reactants)=[[(1Â molÂ CO(g)/mol-rxn)Î”fGÂ°[CO(g)]+(1Â molÂ H2(g)/mol-rxn)Î”fGÂ°[H2(g)]]âˆ’[(1Â molÂ C(s)/mol-rxn)Î”fGÂ°[C(s)]+(1Â molÂ H2O(g)/mol-rxn)Î”fGÂ°[H2O(g)]]Â ]Â

Substitute the values,

Î”rGÂ°=[[(1Â molÂ CO(g)/mol-rxn)(âˆ’137.168Â kJ/mol)+(1Â molÂ H2(g)/mol-rxn)(0Â kJ/mol)]âˆ’[(1Â molÂ C(s)/mol-rxn)(0Â kJ/mol)+(1Â molÂ H2O(g)/mol-rxn)(âˆ’228.59Â kJ/mol)]Â ]=+91.42Â kJ/mol-rxn

The Î”rHÂ° for C(s) is 0Â kJ/mol.

The Î”rHÂ° for H2O(g) is âˆ’241.83Â kJ/mol.

The Î”rHÂ° for CO(g) is âˆ’110.525Â kJ/mol.

The Î”rHÂ° for H2(g) is 0Â kJ/mol

Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started