Holooly Plus Logo
Holooly Plus Logo

Question 3.58: The ΔH° rxn for abstracting each of the possible hydrogen at......

The ΔH°_{rxn} for abstracting each of the possible hydrogen atoms of propane by a bromine atom is indicated below. Based on the data and the fact that the starting materials are the same, what might be surmised about the relative energies of activation for the two reactions?
Do the transition states more closely resemble the reactants or the products?

\mathrm{CH}_{3}{\mathrm{-CH}}_{2}{\mathrm{-CH}}_{3}+\,\mathrm{Br}\quad\qquad{\mathrm{CH}}_{3}{\mathrm{-CH}}_{2}{\mathrm{-CH}}^. _{2}\ +{\mathrm{HBr}} \ \ \ \ ΔH° = +42  kJ  mole^{−1}\\ \mathrm{CH}_{3}{\mathrm{-CH}}_{2}{\mathrm{-CH}}_{3}+\mathrm{Br}\quad\quad\quad\mathrm{CH}_{3}— \dot{CH}— {\mathrm{-CH}}_{3}+\mathrm{HBr} \ \ \ \ ΔH° = +29  kJ  mole^{−1}
Step-by-Step
The 'Blue Check Mark' means that this solution was answered by an expert.
Learn more on how do we answer questions.
Report Answer

The activation energy must be larger for the first reaction listed because it is the more endothermic reaction. The transition state for this reaction must more closely resemble the product than for the second reaction.

Related Answered Questions

Question: 3.59

The ΔH° rxn for abstracting each of the possible hydrogen atoms of propane by a bromine atom is indicated below. Based on the data and the fact that the starting materials are the same, what might be surmised about the relative energies of activation for the two reactions? Do the transition states ...

Verified Answer:

The activation energy must be smaller for the seco...
Question: 3.53

In the presence of a strong acid, tert-butyl alcohol acts as a base. The resulting conjugate acid produces water and an intermediate. Write the structure of the intermediate. What type of bond cleavage occurs? ...

Verified Answer:

Heterogenic cleavage of a C—O bond.
Question: 3.54

Dimethyl ether (CH3—O—CH3) can be prepared by adding a strong base such as NaH to methanol (CH3OH) and then adding iodomethane (CH3I) to the reaction mixture. Write plausible steps for this reaction. ...

Verified Answer:

Question: 3.55

What are the differences between a reaction intermediate and a transition state. ...

Verified Answer:

An intermediate, although short lived, can be dete...
Question: 3.56

A reaction occurs in three steps. How many transition states are there? How many intermediates form? ...

Verified Answer:

There are three transitions states—one for each st...
Question: 3.57

Draw a reaction coordinate diagram for a two-step exothermic reaction in which the second step is a rate-determining. ...

Verified Answer:

Question: 3.48

Consider the activation energies for the following nucleophilic substitution reactions. Which reaction occurs at the faster rate? CH3−I + Cl^− → CH3−Cl + I^−   Ea = 104 kJ mole^−1 CH3−I + Br^− → CH3−Br + I^−   Ea = 96 kJ mole^−1 ...

Verified Answer:

The reaction of bromide ion with iodomethane has t...
Question: 3.45

Given the following information about two reactions, which one will occur at the faster rate at a common temperature? Reaction ΔH^o rxn Ea A → X –120 kJ mole^−1 +100 kJ mole^−1 B → Y –100 kJ mole^−1 +120 kJ mole^−1 ...

Verified Answer:

The reaction converting A to X has the lower activ...
Question: 3.49

Sodium cyanide reacts with chloroethane by the following equation. When the concentration of cyanide ion is tripled, the reaction rate triples. When the concentration of chloroethane doubles, the reaction rate doubles. What is the overall kinetic order of the ...

Verified Answer:

The rate of reaction is first order in both chloro...
Question: 3.51

Identify the processes of bond cleavage and bond formation for each of the following reactions. ...

Verified Answer:

(a) Homolytic cleavage of a C—H bond and homogenic...