Chapter 11 - Acids and Bases - 11.5 Dissociation of Water - Questions and Problems - Page 416: 11.40

a. $[H_3O^+] = 1.0 \times 10^{-12} \space M$ b.$[H_3O^+] = 1.0 \times 10^{-9} \space M$ c.$[H_3O^+] = 5.6 \times 10^{-4} \space M$ d.$[H_3O^+] = 4.0 \times 10^{-9} \space M$

a. $$[H_3O^+] = \frac{1.0 \times 10^{-14}}{[OH^-]} = \frac{1.0 \times 10^{-14}}{ 0.010 } = 1.0 \times 10^{-12} \space M$$ b.$$[H_3O^+] = \frac{1.0 \times 10^{-14}}{[OH^-]} = \frac{1.0 \times 10^{-14}}{ 1.0 \times 10^{-5} } = 1.0 \times 10^{-9} \space M$$ c.$$[H_3O^+] = \frac{1.0 \times 10^{-14}}{[OH^-]} = \frac{1.0 \times 10^{-14}}{ 1.8 \times 10^{-11} } = 5.6 \times 10^{-4} \space M$$ d.$$[H_3O^+] = \frac{1.0 \times 10^{-14}}{[OH^-]} = \frac{1.0 \times 10^{-14}}{ 2.5 \times 10^{-6} } = 4.0 \times 10^{-9} \space M$$