6. Thermodynamics and Kinetics

If ΔG° for a particular reaction is < 0 kcal/mol, which side of the reaction is favored?

If a particular acid/base reaction has a K_eq = 10²⁷, how will ΔG° vary with temperature?

(•••) Looking ahead In Chapter 5, we explain that the equilibrium constant (Kₑ_q) for a reaction can be calculated based on the difference in energy between reactants and products, according to the following equation: Kₑ_q = e ^ -∆E/RT Using this equation, calculate the equilibrium constant for the 'reaction' shown. [For the rest of the book, if not otherwise specified, assume room temperature (298K).]

The following reaction has a value of ΔG= -2.1 kJ/mol (-0.50 kcal/mol). CH3Br + H2S ⇌ CH3SH + HBr a. Calculate Keq at room temperature (25 °C) for this reaction as written.

The following reaction has a value of ΔG= -2.1 kJ/mol (-0.50 kcal/mol). CH3Br + H2S ⇌ CH3SH + HBr b. Starting with a 1 M solution of CH3Br and H2S, calculate the final concentrations of all four species at equilibrium.

a. Which reaction has a greater equilibrium constant: one with a rate constant of 1 * 10-3 sec-1 for the forward reaction and a rate constant of 1 * 10-5 sec-1 for the reverse reaction, or one with a rate constant of 1 * 10-2 sec-1 for the forward reaction and a rate constant of 1 * 10-3 sec-1 for the reverse reaction? b. If both reactions start with a reactant concentration of 1.0 M, which reaction will form the most product when the reactions have reached equilibrium?