Skip to main content
Ch.4 - The Study of Chemical Reactions
Wade - Organic Chemistry 9th Edition
Wade9th EditionOrganic ChemistryISBN: 9780135213728당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Wade 9th EditionCh.4 - The Study of Chemical Reactions문제 41d
4장, 문제 41d

Use bond-dissociation enthalpies (Table 4-2, p. 167) to calculate values of ΔH° for the following reactions.
d. CH3CH2CH3 + H2 → CH3CH3 + CH4

검증된 단계별 안내
1
Identify the bonds broken and formed in the reaction. In this case, the bonds broken are one C-H bond in CH3CH2CH3 (propane) and one H-H bond in H2. The bonds formed are one C-H bond in CH3CH3 (ethane) and one C-H bond in CH4 (methane).
Refer to the bond-dissociation enthalpy table (TABLE 4-2, p. 167) to find the bond-dissociation enthalpy values for each bond involved. For example, the bond-dissociation enthalpy for a C-H bond and an H-H bond will be listed in the table.
Calculate the total energy required to break the bonds. This is done by summing the bond-dissociation enthalpy values for the bonds broken (C-H in propane and H-H in H2).
Calculate the total energy released when the new bonds are formed. This is done by summing the bond-dissociation enthalpy values for the bonds formed (C-H in ethane and C-H in methane).
Determine the overall enthalpy change (ΔH°) for the reaction by subtracting the total energy released (bonds formed) from the total energy required (bonds broken). Use the formula: ΔH° = Σ(bonds broken) - Σ(bonds formed).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
5m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Bond-Dissociation Enthalpy

Bond-dissociation enthalpy (BDE) is the energy required to break a specific bond in a molecule, resulting in the formation of free radicals. It is a crucial concept in thermochemistry, as it helps predict the stability of molecules and the energy changes during chemical reactions. BDE values are typically expressed in kilojoules per mole (kJ/mol) and vary depending on the type of bond and the molecular environment.
추천 영상:
04:09
How to calculate enthalpy using bond dissociation energies.

Enthalpy Change (ΔH°)

The enthalpy change (ΔH°) of a reaction is the difference in enthalpy between the products and reactants under standard conditions. It indicates whether a reaction is exothermic (releases heat, ΔH° < 0) or endothermic (absorbs heat, ΔH° > 0). Calculating ΔH° using bond-dissociation enthalpies involves summing the BDEs of bonds broken in the reactants and subtracting the BDEs of bonds formed in the products.
추천 영상:
04:38
Calculating Enthalpies

Reaction Mechanism

A reaction mechanism describes the step-by-step sequence of elementary reactions by which overall chemical change occurs. Understanding the mechanism is essential for predicting the products and energy changes in a reaction. In the context of the given reaction, recognizing the bonds involved and their respective BDEs allows for accurate calculation of the overall enthalpy change, reflecting the energy dynamics of the process.
추천 영상:
02:16
Heck Reaction Mechanism
관련 실천
교과서 질문

Use the information in Table 4-2 (p. 167) to rank the following radicals in decreasing order of stability.

870
views
교과서 질문

Use bond-dissociation enthalpies (Table 4-2, p. 167) to calculate values of ΔH° for the following reactions.

a. CH3—CH3 + I2 → CH3CH2I + HI

1574
views
교과서 질문

Use bond-dissociation enthalpies (Table 4-2, p. 167) to calculate values of ΔH° for the following reactions.

c. (CH3)3C—OH + HCl → (CH3)3C—Cl + H2O

1225
views
교과서 질문

For each alkane,

1. draw all the possible monochlorinated derivatives.

a. Cyclopentane

b. Methylcyclopentane

920
views
교과서 질문

For each alkane,

2. determine whether free-radical chlorination would be a good way to make any of these monochlorinated derivatives. Will the reaction give mostly one major product?

a. Cyclopentane

b. Methylcyclopentane

932
views
교과서 질문

Use bond-dissociation enthalpies (Table 4-2, p. 167) to calculate values of ΔH° for the following reactions.

b. CH3CH2Cl + HI → CH3CH2I + HCl

1416
views