(ii) Which side of the reaction is favored by entropy? (iii) If ∆S° = 0 for these reactions, calculate ∆G° (Assume T = 298 K) [BDE for O―H = 110 kcal /mol.]

(b)

Predict which side of the equilibrium is favored for each of the chair–chair interconversions (ring flips) shown.

(a)

Predict which side of the equilibrium is favored for each of the chair–chair interconversions (ring flips) shown.

(c)

Which is the most stable base in each pair?

(a)

Which is the most stable base in each pair?

(b) HS^– and HO^–

Which is the most stable base in each pair?

(c) NH₃ vs. H₂O

Which is the most acidic compound in each pair?

(a)

Which is the most acidic compound in each pair?

(b) HF vs. HCl

Which is the most acidic compound in each pair?

(c)

Provide a reasonable arrow-pushing mechanism for the following Lewis acid–Lewis base reactions.

(a)

Provide a reasonable arrow-pushing mechanism for the following Lewis acid–Lewis base reactions.

(b)

Chapter 5 taught us that chemical reactions are random collisions. Experimentally, how can we make molecules collide more often?

For the following equilibrium processes and the corresponding ∆G°, indicate whether you expect the equilibrium constant to be greater than, equal to, or less than 1. Justify your expectation in words.

(a)

For the following equilibrium processes and the corresponding ∆G° , indicate whether you expect the equilibrium constant to be greater than, equal to, or less than 1. Justify your expectation in words.

(b)

For the following equilibrium processes and the corresponding ∆G°, calculate (i) K_eq and (ii) the % composition of the equilibrium mixture (% reactants, % products) at 298 K.

(a)

For the following equilibrium processes and the corresponding ∆G°, calculate (i) K_eq and (ii) the % composition of the equilibrium mixture (% reactants, % products) at 298 K.

(b)

For the following values of ∆H° , ∆S°, and T, tell whether the process would be favored.

(a) ∆H° = -15 kcal/mol ; ∆S° = +37 cal/mol•K ; T = 273 K

For the following values of ∆H° , ∆S°, and T, tell whether the process would be favored.

(b) ∆H° = +7.34 kcal/mol ; ∆S° = +43 cal/mol•K ; T = 325 K

For the following values of ∆H° , ∆S°, and T, tell whether the process would be favored.

(c) ∆H° = -21.3 kcal/mol ; AS° = -51 cal/mol•K ; T = 373 K

For the following values of ∆H° , ∆S°, and T, tell whether the process would be favored.

(d) ∆H° = -8.3 kcal/mol ; ∆S° = -12 cal/mol•K ; T = 298 K

At what temperature does the entropy change of a process not contribute to the favorability of a process?

A certain process has ∆H° = 11.7 kcal/mol and AS° = +33cal/mol•K . That is, this reaction has an unfavorable enthalpy but a favorable entropy term. At what temperature will the process be neither favored nor disfavored?

Considering the process described in Assessment 5.13, will it be favored or disfavored at a temperature higher than the one you calculated? How about at a temperature below what you calculated?

Calculate ∆H° for the following equilibrium processes.

(a)

Calculate ∆H° for the following equilibrium processes.

(b)

Calculate ∆H° for the following equilibrium processes.

(d)

Which conformation in each of the following pairs has the least strain energy?

(a)

Which conformation in each of the following pairs has the least strain energy?

(b)

Which conformation in each of the following pairs has the least strain energy?

(c)