/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 73 Using values from Appendix \(C\)... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 5: Problem 73

Using values from Appendix \(C\), calculate the standard enthalpy change for each of the following reactions: (a) \(2 \mathrm{SO}_{2}(g)+\mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{SO}_{3}(g)\) (b) \(\mathrm{Mg}(\mathrm{OH})_{2}(s) \longrightarrow \mathrm{MgO}(s)+\mathrm{H}_{2} \mathrm{O}(l)\) (c) \(\mathrm{N}_{2} \mathrm{O}_{4}(g)+4 \mathrm{H}_{2}(g) \longrightarrow \mathrm{N}_{2}(g)+4 \mathrm{H}_{2} \mathrm{O}(g)\) (d) \(\mathrm{SiCl}_{4}(l)+2 \mathrm{H}_{2} \mathrm{O}(l) \longrightarrow \mathrm{SiO}_{2}(s)+4 \mathrm{HCl}(g)\)

Short Answer

Expert verified
The standard enthalpy changes for the given reactions are: (a) -197.8 kJ/mol (b) 37.5 kJ/mol (c) -976.36 kJ/mol (d) -51.6 kJ/mol

Step by step solution

01

(a) Reaction: 2 SO鈧�(g) + O鈧�(g) 鈫� 2 SO鈧�(g)

To calculate the standard enthalpy change, we first look up the values of the standard enthalpy of formation (螖H掳f) for each species in the reaction. From Appendix C, we have: \(螖H掳f [SO鈧�(g)] = -296.8 \ \text{kJ/mol}\) Since there is no formation involved in the formation of elemental O鈧�, its value is: \(螖H掳f [O鈧�(g)] = 0\) \(螖H掳f [SO鈧�(g)] = -395.7 \ \text{kJ/mol}\) Now we apply the formula: 螖H掳rxn = 危 n 螖H掳f(products) - 危 n 螖H掳f(reactants) For this reaction, it is: 螖H掳rxn = [2 脳 (-395.7) ] - [ 2 脳 (-296.8) + 1 脳 0] Calculate the value: 螖H掳rxn = -791.4 + 593.6 = -197.8 kJ/mol
02

(b) Reaction: Mg(OH)鈧�(s) 鈫� MgO(s) + H鈧侽(l)

From Appendix C, we have: \(螖H掳f [Mg(OH)鈧�(s)] = -924.9 \ \text{kJ/mol}\) \(螖H掳f [MgO(s)] = -601.6 \ \text{kJ/mol}\) \(螖H掳f [H鈧侽(l)] = -285.8 \ \text{kJ/mol}\) Apply the formula: 螖H掳rxn = [(-601.6) + (-285.8) ] - [ (-924.9)] Calculate the value: 螖H掳rxn = -887.4 + 924.9 = 37.5 kJ/mol
03

(c) Reaction: N鈧侽鈧�(g) + 4 H鈧�(g) 鈫� N鈧�(g) + 4 H鈧侽(g)

From Appendix C, we have: \(螖H掳f [N鈧侽鈧�(g)] = 9.16 \ \text{kJ/mol}\) \(螖H掳f [H鈧�(g)] = 0\) \(螖H掳f [N鈧�(g)] = 0\) \(螖H掳f [H鈧侽(g)] = -241.8 \ \text{kJ/mol}\) Apply the formula: 螖H掳rxn = [1 脳 0 + 4 脳 (-241.8) ] - [ 1 脳 9.16 + 4 脳 0] Calculate the value: 螖H掳rxn = -967.2 - 9.16 = -976.36 kJ/mol
04

(d) Reaction: SiCl鈧�(l) + 2 H鈧侽(l) 鈫� SiO鈧�(s) + 4 HCl(g)

From Appendix C, we have: \(螖H掳f [SiCl鈧�(l)] = -657.5 \ \text{kJ/mol}\) \(螖H掳f [H鈧侽(l)] = -285.8 \ \text{kJ/mol}\) \(螖H掳f [SiO鈧�(s)] = -911.5 \ \text{kJ/mol}\) \(螖H掳f [HCl(g)] = -92.3 \ \text{kJ/mol}\) Apply the formula: 螖H掳rxn = [(-911.5) + 4 脳 (-92.3) ] - [ (-657.5) + 2 脳 (-285.8) ] Calculate the value: 螖H掳rxn = -911.5 - 369.2 + 657.5 + 571.6 = -51.6 kJ/mol So, the standard enthalpy changes for the given reactions are: (a) -197.8 kJ/mol (b) 37.5 kJ/mol (c) -976.36 kJ/mol (d) -51.6 kJ/mol

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.

Over 30 million students worldwide already upgrade their learning with 91影视!

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

A watt is a measure of power (the rate of energy change) equal to \(1 \mathrm{~J} / \mathrm{s}\). (a) Calculate the number of joules in a kilowatthour. (b) An adult person radiates heat to the surroundings at about the same rate as a 100-watt electric incandescent lightbulb. What is the total amount of energy in kcal radiated to the surroundings by an adult in \(24 \mathrm{~h}\) ?

The Sun supplies about \(1.0\) kilowatt of energy for each square meter of surface area \(\left(1.0 \mathrm{~kW} / \mathrm{m}^{2}\right.\), where a watt \(\left.=1 \mathrm{~J} / \mathrm{s}\right)\). Plants produce the equivalent of about \(0.20 \mathrm{~g}\) of sucrose \(\left(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\right)\) per hour per square meter. Assuming that the sucrose is produced as follows, calculate the percentage of sunlight used to produce sucrose. $$ \begin{array}{r} 12 \mathrm{CO}_{2}(g)+11 \mathrm{H}_{2} \mathrm{O}(l) \longrightarrow \mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}+12 \mathrm{O}_{2}(g) \\ \Delta H=5645 \mathrm{~kJ} \end{array} $$

Under constant-volume conditions, the heat of combustion of glucose \(\left(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\right)\) is \(15.57 \mathrm{~kJ} / \mathrm{g}\). A \(3.500-\mathrm{g}\) sample of glucose is burned in a bomb calorimeter. The temperature of the calorimeter increases from \(20.94\) to \(24.72{ }^{\circ} \mathrm{C}\). (a) What is the total heat capacity of the calorimeter? (b) If the size of the glucose sample had been exactly twice as large, what would the temperature change of the calorimeter have been?

The complete combustion of ethanol, \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}(l)\), to form \(\mathrm{H}_{2} \mathrm{O}(g)\) and \(\mathrm{CO}_{2}(g)\) at constant pressure releases \(1235 \mathrm{~kJ}\) of heat per mole of \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\). (a) Write a balanced thermochemical equation for this reaction. (b) Draw an enthalpy diagram for the reaction.

The standard enthalpies of formation of gaseous propyne \(\left(\mathrm{C}_{3} \mathrm{H}_{4}\right)\), propylene \(\left(\mathrm{C}_{3} \mathrm{H}_{6}\right)\), and propane \(\left(\mathrm{C}_{3} \mathrm{H}_{8}\right)\) are \(+185.4,+20.4\), and \(-103.8 \mathrm{~kJ} / \mathrm{mol}\), respectively. (a) Calculate the heat evolved per mole on combustion of each substance to yield \(\mathrm{CO}_{2}(g)\) and \(\mathrm{H}_{2} \mathrm{O}(g)\). (b) Calculate the heat evolved on combustion of \(1 \mathrm{~kg}\) of each substance. (c) Which is the most efficient fuel in terms of heat evolved per unit mass?
See all solutions

Recommended explanations on Chemistry Textbooks

Inorganic Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Chemical Analysis

Read Explanation

Nuclear Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

The Earths Atmosphere

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.