## Chemistry: Atoms First (2nd Edition)

$N{H_3}$, $Cl{O_2}^-$, $H_2O$, $ClO_4^-$
Using the table 13-2, from page 531, and knowing that: Strong acids: $K_a > 1$ $H_3O^+$: $K_a = 1.0$ Identify each acid ka value for the conjugate acids of these compounds: $HClO_2$: $K_a = 1.2 \times 10^{-2}$ $H_3O^+$: $K_a = 1.0$ $N{H_4}^+$: $K_a = 5.6 \times 10^{-10}$ $HClO_4$: $K_a > 1$ - Ordering in decreasing order, we obtain: $HClO_4, H_3O^+, HClO_2, N{H_4}^+$ - The stronger the acid, the weaker its conjugate base, and vice versa. Therefore: the bases in decreasing order are: $NH_3, ClO_2^-, H_2O, ClO_4^-$ - We've inverted the previous order.