Skip to main content
Ch.5 - Thermochemistry
Brown - Chemistry: The Central Science 15th Edition
Brown15th EditionChemistry: The Central ScienceISBN: 9780137542970Non è quello che usi tu?Cambia libro di testo
Tutti i libri di testoBrown 15th EditionCh.5 - ThermochemistryProblema 47a
Capitolo 5, Problema 47a

Consider the combustion of isopropanol, C3H7OH(l), which is the primary component of rubbing alcohol: C3H7OH(l) + 9/2 O2(g) → 3 CO2(g) + 4 H2O(l) ΔH = -2248 kJ a. What is the enthalpy change for the reverse reaction?

Guida verificata passo dopo passo
1
Identify the given reaction: C_3H_7OH(l) + \(\frac{9}{2}\) O_2(g) \(\rightarrow\) 3 CO_2(g) + 4 H_2O(l) with \(\Delta\) H = -2248 \(\text{ kJ}\).
Understand that the enthalpy change (\(\Delta\) H) for a reaction is the energy change when the reaction occurs as written.
For the reverse reaction, the products and reactants are swapped: 3 CO_2(g) + 4 H_2O(l) \(\rightarrow\) C_3H_7OH(l) + \(\frac{9}{2}\) O_2(g).
The enthalpy change for the reverse reaction is the negative of the enthalpy change for the forward reaction.
Calculate the enthalpy change for the reverse reaction by changing the sign of the given \(\Delta\) H: \(\Delta\) H_{reverse} = -(-2248 \(\text{ kJ}\)).

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
1m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Enthalpy Change

Enthalpy change (ΔH) is a measure of the heat absorbed or released during a chemical reaction at constant pressure. In exothermic reactions, like the combustion of isopropanol, ΔH is negative, indicating that heat is released. Understanding enthalpy is crucial for predicting the energy changes associated with chemical reactions, including both forward and reverse processes.
Video consigliato:
Percorso guidato
02:34
Enthalpy of Formation

Combustion Reactions

Combustion reactions involve the reaction of a substance with oxygen, producing heat and light. In the case of isopropanol, the combustion results in carbon dioxide and water as products. Recognizing the characteristics of combustion reactions helps in understanding the energy dynamics and the stoichiometry involved in the reaction, which is essential for calculating enthalpy changes.
Video consigliato:
Percorso guidato
02:24
Combustion Apparatus

Reverse Reaction

The reverse reaction of a chemical process is simply the reaction proceeding in the opposite direction. For the combustion of isopropanol, the reverse reaction would involve the formation of isopropanol from carbon dioxide and water. The enthalpy change for the reverse reaction is equal in magnitude but opposite in sign to that of the forward reaction, which is a fundamental principle in thermodynamics.
Video consigliato:
Percorso guidato
03:42
Reversible Changes in Matter
Pratica correlata
Domanda del libro di testo

At one time, a common means of forming small quantities of oxygen gas in the laboratory was to heat KClO3: 2 KClO3(s) → 2 KCl(s) + 3 O2(g) ΔH = -89.4 kJ For this reaction, calculate H for the formation of (a) 1.36 mol of O2

560
views
Domanda del libro di testo

At one time, a common means of forming small quantities of oxygen gas in the laboratory was to heat KClO3: 2 KClO3(s) → 2 KCl(s) + 3 O2(g) ΔH = -89.4 kJ For this reaction, calculate H for the formation of (b) 10.4 g of KCl.

423
views
Domanda del libro di testo

Consider the decomposition of liquid benzene, C6H6(l), to gaseous acetylene, C2H2(g): C6H6(l) → 3 C2H2(g) ΔH = +630 kJ (a) What is the enthalpy change for the reverse reaction?

803
views
Domanda del libro di testo

Consider the decomposition of liquid benzene, C6H6(l), to gaseous acetylene, C2H2(g): C6H6(l) → 3 C2H2(g) ΔH = +630 kJ (b) What is H for the formation of 1 mol of acetylene?

373
views
Domanda del libro di testo

Consider the combustion of isopropanol, C3H7OH(l), which is the primary component of rubbing alcohol: C3H7OH(l) + 9/2 O2(g) → 3 CO2(g) + 4 H2O(l) ΔH = -2248 kJ (b) Balance the forward reaction with whole-number coefficients. What is ΔH for the reaction represented by this equation?

3
views
Domanda del libro di testo

At one time, a common means of forming small quantities of oxygen gas in the laboratory was to heat KClO3: 2 KClO3(s) → 2 KCl(s) + 3 O2(g) ΔH = -89.4 kJ c. Now consider the reverse reaction, in which KClO3 is formed from KCl and O2. What is Δ𝐻 for the formation of 19.1 g KClO3 from KCl and O2?

5
views