The hydronium ion concentration in a sample of rainwater is found to be \(1.7 \times 1{0^{ - 6}}M\) times 25^oC. What is the concentration of hydroxide ions in the rainwater?

Concentration of the hydronium ions in rain water is \(1.7 \times 1{0^{ - 6}}M\)

The concentration of hydroxide ions can be found from \(pOH\) with the equation\(c\left( {O{H^ - }} \right) = {10^{ - pOH}}mol{L^{ - 1}}\).

Concentration of the hydronium ion is

\(c\left( {{H_3}{O^ + }} \right) = 1.7 \times 1{0^{ - 6}}\frac{{mol}}{L}\)

To calculate concentration of hydroxide ion using ionization constant for water

\({K_w} = c\left( {{H_3}{O^ + }} \right) \times c\left( {O{H^ - }} \right)\)

\(c\left( {O{H^ - }} \right) = \frac{{{K_w}}}{{c\left( {{H_3}{O^ + }} \right)}}\)

Ionization constant for water is\(1.0 \times 1{0^{ - 14}}\)

\(c\left( {O{H^ - }} \right) = \frac{{1.0 \times 1{0^{ - 14}}}}{{1.7 \times 1{0^{ - 6}}}}\)

\(c\left( {O{H^ - }} \right) = 5.8 \times 1{0^{ - 9}}\frac{{mol}}{L}\)