Question

Which of the following aqueous solutions is a buffer with a pH greater than 7.0? For HNO_{2 }, K_a = 4.6 × 10^{-4 }, and for NH_3, K_{b }=1.8 × 10^{-5} (1) 10 mL of 0.1 M NH_3,(aq) + 10 mL of 0.1 M HCl (aq) (2) 10 mL of 0.1 M HNO_2,(aq) + 5.0 mL of O.1 M NaOH (aq) (3) 10 mL of 0.1 M HNO_2,(aq) + 10 mL of 0.1 M NaOH (aq) (4) 10 mL of 0.1 M NH_3, (aq) + 5.0 mL of 0.1 M HCl (aq)

Answer 1