0 votes 0 votes The ion product of water $(pK_w)$ is $14$. If a rain water sample has a $pH$ of $5.6$, the concentration of $OH^-$ in the sample (in $10^{-9}\: \text{mol/litre}$, round off to one decimal place), is ________. Water and Waste Water Quality and Treatment gate2020-ce-2 numerical-answers physical-chemical-and-biological-parameters ph-scale + – go_editor asked Feb 13, 2020 recategorized May 10, 2021 by Chandanachandu go_editor 5.3k points answer See all 0 reply