## Chemistry: Atoms First (2nd Edition)

a. $H_2O$ is the stronger base; b. $N{O_2}^-$ is the stronger base; c. $OC_6{H_5}^-$ is the stronger base;
- Identify the base with the weakest conjugate acid; it will be the stronger base. Using the table 13-2, from page 531, and knowing that: Strong acids: $K_a > 1$ $H_3O^+$: $K_a = 1.0$ a. $HCl$ has $K_a > 1$ $H_3O^+$ has $K_a = 1$ Therefore, $H_3O^+$ is the weaker acid, and $H_2O$ is the stronger base. b. $H_3O^+$ has $K_a = 1$ $HNO_2$ has $K_a = 4.0 \times 10^{-4}$ Therefore, $HNO_2$ is the weaker acid, and $N{O_2}^-$ is the stronger base. c. $HCN$ has $K_a = 6.2 \times 10^{-10}$ $HOC_6H_5$ has $K_a = 1.6 \times 10^{-10}$ Therefore, $HOC_6H_5$ is the weaker acid, and $OC_6{H_5}^-$ is the stronger base