Exam 4: The Study of Chemical Reactions

Consider the reaction of A being converted into B at 25°C. If the ΔG° of this reaction is +0.5 kcal/mol, the K_eq is ________ and the % conversion is ________.

Given an activation energy of 15 kcal/mol, use the Arrhenius equation to estimate how much faster the reaction will occur if the temperature is increased from 100°C to 120°C. R = 1.987 cal/mol∙K.

Assume the reaction A + B → C + D proceeds to equilibrium. Calculate the equilibrium concentration of D at 25°C, given that the starting concentrations of A and B are 2M and that ΔG° for the reaction is 1.0 kcal/mol. R = 1.987 cal/mol∙K.

Which of the following reactive intermediate species maintains sp³ hybridization?

Consider the elementary step in the solvolysis of isopropyl chloride shown below and write the rate equation for this step. (CH₃)₂CHCl → (CH₃)₂CH⁺ + Cl^-

What is the relative reactivity of 2° vs 1° hydrogens in the free radical bromination of n-butane if the ratio of 1-bromobutane to 2-bromobutane formed is 7:93?

Predict the enthalpy (ΔH) value for the theoretical reaction below, and indicate whether it is endothermic or exothermic. The bond dissociation energy for each bond in Kcal/mol is shown below each reactant and product.

When two carbenes collide, they immediately dimerize to give ________.

Consider the conversion of X to Z through the sole intermediate Y. Given the reaction-energy diagram shown below, which step is the rate-limiting step? Explain your reasoning.

Provide the major organic product(s) in the reaction below.

In the reaction of Cl₂ with ethane and UV light, which of the following reactions would be a chain termination event(s)? I. Cl∙ + CH₃-CH₃ → CH₃-CH₂-Cl + H∙ II. Cl∙ + CH₃-CH₃ → CH₃-H₂C∙ + HCl III. Cl∙ + CH₃-H₂C∙ → CH₃-CH₂-Cl IV. Cl₂ + CH₃-H₂C∙ → CH₃-CH₂-Cl + Cl∙ V. Cl_{2 + UV light} → C l∙ + Cl∙

Explain the significance of the exponential factor e^-Ea/RT in the Arrhenius equation.

The Arrhenius equation mathematically models which of the following statements?

Consider the one-step conversion of F to G. Given that the reaction is endothermic by 5 kcal/mol and that the energy difference between G and the transition state for the process is 15 kcal/mol, sketch a reaction-energy diagram for this reaction. Make sure to show how the given energy differences are consistent with your sketch.

What is the name of the major monobrominated product which results when 3-methylpentane is subjected to Br₂/hν conditions?

When acetaldehyde (CH₃CHO) is deprotonated, the resulting anion is stabilized by resonance. Draw the major resonance contributing forms of this anion.

Which of the presented mechanisms would be the most energetically favorable and thus the most likely mechanism to actually occur for the following free radical chain reaction? (bond dissociation energies -- H-H = 104 kcal/mol; Cl-Cl = 58 kcal/mol; H-Cl = 103 kcal/mol) H₂ + Cl₂ 2 HCl

What reactive species is produced in the initiation step of the free radical chlorination of 2,2-dimethylpropane?

Which of the following is a carbene?

How many distinct monochlorinated products can result when isobutane is subjected to free radical chlorination?