   Chapter 17, Problem 66E

Chapter
Section
Textbook Problem

# Using data from Appendix 4, calculate ∆G for the reaction 2 H 2 S ( g ) + SO 2 ( g ) ⇌ 3 S rhombic ( s ) + 2 H 2 O ( g ) for the following conditions at 25°C: P H 2 S = 1.0 × 10 − 4 atm P SO 2 = 1.0 × 10 − 2 atm P H 2 O = 3.0 × 10 − 2 atm

Interpretation Introduction

Interpretation: The reaction of H2S and SO2 , pressure of each reactant, product and value of temperature of this reaction is given. The value of ΔG is to be calculated by using data from Appendix 4 .

Concept introduction: Reaction quotient, Q , is the measure of concentration or partial pressure of reactants and products of a system before equilibrium point is reached.

ΔG=ΔG°+RTln(Q)

Explanation

Explanation

The reaction that takes place is,

2H2S(g)+SO2(g)3Srhombic(s)+2H2O(g)

Refer to Appendix 4 .

The value of ΔG°(kJ/mol) for the given reactant and product is,

 Molecules ΔG°(kJ/mol) H2S(g) −34 SO2(g) −300 Srhombic(g) 0 H2O(g) −229

The formula of ΔG° is,

ΔG°=npΔG°(product)nfΔG°(reactant)

Where,

• np is number of moles of each product.
• nr is number of moles each reactant.
• ΔG°(product) is free energy of product at a pressure of 1atm .
• ΔG°(reactant) is free energy of reactant at a pressure of 1atm .

Substitute all values from the table in the above equation.

ΔG°=npΔG°(product)nfΔG°(reactant)=[3(0)+2(229){2(34)+(300)}]kJ=90kJ_

Given

Pressure of H2S , PH2S , is 1.00×104atm .

Pressure of SO2 , PSO2 , is 1.00×102atm .

Pressure of H2O , PH2O , is 3.00×102atm .

Formula

The reaction quotient, is expressed by the formula,

Q=PressureofproductsPressureofreactants

Where,

• Q is the reaction quotient.

The reaction quotient expression for the given reaction is,

Q=(PH2O)2(PH2S)2(PSO2)

Substitute the values of PH2O,PH2S and PSO2 in the above expression

### 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 