WCB Quiz: Driving Force for Reactions - DG, D Gostab, D Gconc,

1. Consider the reaction HCl+H20 --> H3O+ + Cl-. At t=0, 0.1 mol of HCl is added to 1L of water. At t=0, which favors the forward reaction? (For all questions, R/P means Reactants and Products)

a. both relative concentration of R/P AND relative reactivity of R/P. since HCl is a strong acid and completely dissociates into ions - HCl is stronger than hydronium ion; Also, no products to reverse rx.

b. neither relative concentration of R/P or relative reactivity of R/P.

c. relative concentration of R/P alone.

d. relative reactivity of R/P alone.

2. For the reaction in 1, which favors the forward reaction at equilibrium?

a. relative concentration of R/P alone.

b. relative reactivity of R/P alone. At eq., there is no HCl so concentration can't favor the forward rx. Based on relative reactivity of HCl vs H3O+, reaction still favored to go forward (even though there is no HCl).

c. both relative concentration of R/P AND relative reactivity of R/P.

d. neither relative concentration of R/P or relative reactivity of R/P.

3. For the reaction in 1, which favors the forward reaction at t=0?

a. ΔGconc, alone

b. ΔGostab alone

c. both DGostab and DGconc. Same as question 1. since HCl is a strong acid and completely dissociates into ions - HCl is stronger than hydronium ion, DGostab < 0; Also, no products to reverse rx.

d. neither ΔGostab and ΔGconc.

4. For the reaction in 1, which favors the forward reaction at equilibrium?

a. ΔGconc alone

b. DGostab alone. Same as Question 2

c. both ΔGostab and ΔGconc.

d. neither ΔGostab and ΔGconc.

5. Consider the reaction CH3COOH +H20 --> H3O+ + CH3COO-. At t=0, 0.1 mol of CH3COOH is added to 1L of water. At t=0, which favors the forward reaction?

a. relative reactivity of R/P alone.

b. relative concentration of R/P alone. Relative reactivity favors reverse rx - formation of weaker acid

c. both relative concentration of R/P AND relative reactivity of R/P.

d. neither relative concentration of R/P or relative reactivity of R/P.

6. For the reaction in 5, which favors the forward reaction at equilibrium?

a. relative reactivity of R/P alone.

b. both relative concentration of R/P AND relative reac ivity of R/P.

c. relative concentration of R/P alone. Relative reactivity still favors reverse rx.

d. neither relative concentration of R/P or relative reactivity of R/P.

7. For the reaction in 5, which favors the forward reaction at t=0?

a. DGconc alone. Only concentration favors forward rx.

b. ΔGostab alone

c. both ΔGostab and ΔGconc.

d. neither ΔGostab and ΔGconc.

8. For the reaction in 5, which favors the forward reaction at equilibrium?

a. DGconc alone. Reactivity still favors reverse rx. At eq. , still more reactants than products

b. ΔGostab alone

c. both ΔGostab and ΔGconc.

d. neither ΔGostab and ΔGconc.