Which of the following chemical equations corresponds to the base ionization constant, K_b, for nitrite ion (NO^-_2)? a. HNO_2(aq) + H_2O(l) rightarrow NO^-_2 (aq) + H_3O^+(aq) b. NO^-_2(aq) + H_2O(l) rightarrow HNO_2(aq) + OH^-(aq) c. HNO_2(aq) + OH^-(aq) rightarrow NO^-_2(aq) + H_2O(l) d. NO^-_2(aq) + OH^-(aq) rightarrow HNO^2-_3 (aq) e. NO^+_2(aq) + H_3O^+(aq) rightarrow HNO_2(aq) + H_2O(l) Assuming equal initial concentrations of the given species, which of the following weak acids has the strongest conjugate base in an aqueous solution? a. acetic acid, K_a = -1.8 times 10^-5 b. formic acid, K_a = 1.8 times 10^-4 c. hydrogen sulfite ion, K_a = 6.2 times 10^-8 d. nitrous acid, K_a = 4.5 times 10^-4 e. phosphoric acid, K_a = 7.5 times 10^-3 Which salt produces a pH-neutral aqueous solution at 25 degree C? a. KBr b. NH_4Cl c. NaNO_2 d. KF e. FeCl_3 Given the following acid dissociation constants, K_a(HF) = 7.2 times 10^-4 K_a (NH^+_4) = 5.6 times 10^-10 determine the equilibrium constant for the reaction below at 25 degree C. HF(aq) + NH_3(aq) rightarrow NH^+_4(aq) + F^-(aq) a. 4.0 times 10^-13 b. 1.3 times 10^-8 c. 7.8 times 10^-7 d. 1.3 times 10^6 e. 2.5 times 10^12 What is the H_3O^+ concentration in 0.45 M HCN(aq)? (K_a of HCN = 4.0 times 10^-10) a. 4.0 times 10^-10 M b. 1.8 times 10^-10 M c. 1.3 times 10^-5 M d. 2.0 times 10^-5 M e. 0.45 M What is the pH of 0.015 M aqueous benzoic acid? (K_a of C_5H_6CO_2H = 6.3 times 10^-5) a. 1.82 b. 3.03 c. 4.20 d. 6.02 e. 12.18