Concept explainers
Calculate ΔH° for each of the following reactions, which occur in the atmosphere.
a. C2H4(g) + O3(g) → CH3CHO(g) + O2(g)
b. O3(g) + NO(g) → NO2(g) + O2(g)
c. SO3(g) + H2O(l) → H2SO4(aq)
d. 2NO(g) + O2(g) → 2SO2(g)
(a)
Interpretation: For given reactions, standard enthalpy change has to be calculated.
Concept introduction
Standard Enthalpy change (
Answer to Problem 121AE
Explanation of Solution
Explanation
Given: Standard enthalpy value for given substance in the reactions are,
Substance and state
|
|
Standard enthalpy values for given substances in the reaction are shown above.
To calculate standard enthalpy change for given reaction.
The standard enthalpy change for given equation is -361 kJ .
=
=
The standard enthalpy change for the reaction can be calculated by enthalpy of product versus enthalpy of reactant. The standard enthalpy values for given substances in a reaction are shown (Table.1). By substituting these values in standard enthalpy change equation the standard enthalpy change for the reaction has calculated as -361 k J .
(b)
Interpretation: For given reactions, standard enthalpy change has to be calculated.
Concept introduction
Standard Enthalpy change (
Answer to Problem 121AE
Explanation of Solution
Given: Standard enthalpy value for given substance in the reactions are,
Substance and state
|
|
Standard enthalpy values for given substances in the reaction are shown above.
To calculate standard enthalpy change for given equation.
The standard enthalpy change for given equation is -199kJ.
The standard enthalpy change for the reaction can be calculated by enthalpy of product versus enthalpy of reactant. The standard enthalpy values for given substances in a reaction are shown (Table.1). By substituting these values in standard enthalpy change equation the standard enthalpy change for the reaction has calculated as -199kJ.
(c)
Interpretation: For given reactions, standard enthalpy change has to be calculated.
Concept introduction
Standard Enthalpy change (
Answer to Problem 121AE
Explanation of Solution
Explanation:
Given: Standard enthalpy value for given substance in the reactions are,
Substance and state
|
|
Standard enthalpy values for given substances in the reaction are shown above.
To calculate standard enthalpy change for given equation.
The standard enthalpy change for given equation is -227kJ .
The standard enthalpy change for the reaction can be calculated by enthalpy of product versus enthalpy of reactant. The standard enthalpy values for given substances in a reaction are shown (Table.1). By substituting these values in standard enthalpy change equation the standard enthalpy change for the reaction has calculated as -227kJ. .
(d)
Interpretation: For given reactions, standard enthalpy change has to be calculated.
Concept introduction
Standard Enthalpy change (
Answer to Problem 121AE
Explanation of Solution
Explanation:
Given: Standard enthalpy value for given substance in the reactions are,
Substance and state
|
|
Standard enthalpy values for given substances in the reaction are shown above.
To calculate standard enthalpy change for given equation.
The standard enthalpy change for given equation is -112kJ.
The standard enthalpy change for the reaction can be calculated by enthalpy of product versus enthalpy of reactant. The standard enthalpy values for given substances in a reaction are shown (Table.1). By substituting these values in standard enthalpy change equation the standard enthalpy change for the reaction has calculated as -112kJ .
Want to see more full solutions like this?
Chapter 6 Solutions
Chemistry
- Oxygen was first prepared by Joseph Priestley (1733-1804) by heating HgO. Use data in Appendix L to estimate the temperature required to decompose HgO(s) into Hg() and O2(g).arrow_forwardConsider the Haber process: N2(g)+3H2(g)2NH3(g);H=91.8kJ The density of ammonia at 25C and 1.00 atm is 0.696 g/L. The density of nitrogen, N2, is 1.145 g/L, and the molar heat capacity is 29.12 J/(mol C). (a) How much heat is evolved in the production of 1.00 L of ammonia at 25C and 1.00 atm? (b) What percentage of this heat is required to heat the nitrogen required for this reaction (0.500 L) from 25C to 400C, the temperature at which the Haber process is run?arrow_forwardUsing data from Appendix 4, calculate H, S and G for the following reactions that produce acetic acid: Which reaction would you choose as a commercial method for producing acetic acid (CH3CO2H) at standard conditions? What temperature conditions would you choose for the reaction? Assume H and S do not depend on temperature.arrow_forward
- An industrial process for manufacturing sulfuric acid, H2SO4, uses hydrogen sulfide, H2S, from the purification of natural gas. In the first step of this process, the hydrogen sulfide is burned to obtain sulfur dioxide, SO2. 2H2S(g)+3O2(g)2H2O(l)+2SO2(g);H=1124kJ The density of sulfur dioxide at 25C and 1.00 atm is 2.62 g/L, and the molar heat capacity is 30.2 J/(mol C). (a) How much heat would be evolved in producing 1.00 L of SO2 at 25C and 1.00 atm? (b) Suppose heat from this reaction is used to heat 1.00 L of the SO2 from 25C to 500C for its use in the next step of the process. What percentage of the heat evolved is required for this?arrow_forwardCalculate H for each of the following reactions using the data in Appendix 4: 4Na(s)+O2(g)2Na2O(s)2Na(s)+2H2O(l)2NaOH(aq)+H2(g)2Na(s)+CO2(g)Na2O(s)+CO(g) Explain why a water or carbon dioxide fire extinguisher might not be effective in putting out a sodium fire.arrow_forwardAt 298 K, the standard enthalpies of formation for C2H2(g) and C6H6(l) are 227 kJ/mol and 49 kJ/mol, respectively. a. Calculate H for C6H6(l)3C2H2(g) b. Both acetylene (C2H2) and benzene (C6H6) can be used as fuels. Which compound would liberate more energy per gram when combusted in air?arrow_forward
- Use Appendix L to find the standard enthalpies of formation of oxygen atoms, oxygen molecules (O2), and ozone (O3). What is the standard state of oxygen? Is the formation of oxygen atoms from O2 exothermic? What is the enthalpy change for the formation of 1 mol of O3 from O2?arrow_forwardCalcium carbide, CaC2, is manufactured by reducing lime with carbon at high temperature. (The carbide is used in turn to make acetylene, an industrially important organic chemical.) Is the reaction endothermic or exothermic?arrow_forwardFor the reaction HgO(s)Hg(l)+12O2(g),H=+90.7kJ: a.What quantity of heat is required to produce 1 mole of mercury by this reaction? b.What quantity of heat is required to produce 1 mole of oxygen gas by this reaction? c.What quantity of heat would be released in the following reaction as written? 2Hg(l) + O2(g) 2HgO(s)arrow_forward
- Use the values of Hf in Appendix 4 to calculate H for the following reactions. (See Exercise 77 .) a. b. SiCl4(l)+2H2O(l)SiO2(s)+4HCl(aq) c. MgO(s)+H2O(l)Mg(OH)2(s)arrow_forwardThe thermochemical equation for the burning of methane, the main component of natural gas, is CH4(g)+2O2(g)CO2(g)+2H2O(l)H=890kJ (a) Is this reaction endothermic or exothermic? (b) What quantities of reactants and products are assumed if H = 890 kJ? (c) What is the enthalpy change when 1.00 g methane burns in an excess of oxygen?arrow_forwardFor each of the following processes, predict the algebraic sign of rH, rS, and rG. No calculations are necessary; use your common sense. (a) The decomposition of liquid water to give gaseous oxygen and hydrogen, a process that requires a considerable amount of energy. (b) Dynamite is a mixture of nitroglycerin, C3H5N3O9, and diatomaceous earth. The explosive decomposition of nitroglycerin gives gaseous products such as water, CO2, and others; much heat is evolved. (c) The combustion of gasoline in the engine of your car, as exemplified by the combustion of octane. 2 C8H18(g) + 25 O2(g) 16 CO2(g) + 18 H2O(g)arrow_forward
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage Learning
- Chemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning