Definition of $pH$ and $pOH$

Tutorial 7

        

Ionization of water, pH and pOH definition $ [\; ] $ Denotes molarity = concentration in mole per liter $ H_3O^+ $ is the hydronium ion $ OH^- $ is the hydroxide ion Ionization of water $ 2H_2O $ $ \leftrightarrows $ $H_3O^+ $ $ + $ $OH^- $ $ [H_3O^+] [OH^-] $ $ = $ $ 10^{-14} $ $ = $ $ K_e $ This relationship is valid both for pure water and for any dilute aqueous solution STP Definition of pH $pH$ $=$ $-log[H_3O^+]$ so: $[H_3O^+]$ $=$ $10^{-pH}$ Definition of pOH $pOH$ $=$ $-log[OH^-]$ so: $[OH^-]$ $=$ $10^{-pOH}$ Relation between pH and pOH $pOH$ $+$ $pOH$ $=$ $14$ This relationship holds for both pure water and any dilute aqueous solution STP

$[OH^-]$ in a solution is $8,5 \cdot 10^{-5}\; M$. What is the $pH$?

a) $8.50$ b) $4.07$ c) $7.00$ d) $9.93$

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