## Chemistry (4th Edition)

(a) $[H_3O^+] = 4 \times 10^{- 13}M$ (b) $[H_3O^+] = 5.98 \times 10^{- 10}M$ (c) $[H_3O^+] = 1.16 \times 10^{- 12}M$ (d) $[H_3O^+] = 5.71 \times 10^{- 3}M$
(a) $[OH^-] * [H^+] = Kw = 10^{-14}$ $2.5 \times 10^{- 2} * [H^+] = 10^{-14}$ $[H^+] = \frac{10^{-14}}{ 2.5 \times 10^{- 2}}$ (b) $[OH^-] * [H^+] = Kw = 10^{-14}$ $1.67 \times 10^{- 5} * [H^+] = 10^{-14}$ $[H^+] = \frac{10^{-14}}{ 1.67 \times 10^{- 5}}$ $[H^+] = 5.98 \times 10^{- 10}$ (c) $[OH^-] * [H^+] = Kw = 10^{-14}$ $8.62 \times 10^{- 3} * [H^+] = 10^{-14}$ $[H^+] = \frac{10^{-14}}{ 8.62 \times 10^{- 3}}$ $[H^+] = 1.16 \times 10^{- 12}$ (d) $[OH^-] * [H^+] = Kw = 10^{-14}$ $1.75 \times 10^{- 12} * [H^+] = 10^{-14}$ $[H^+] = \frac{10^{-14}}{ 1.75 \times 10^{- 12}}$ $[H^+] = 5.71 \times 10^{- 3}$