How do you determine the pH of a solution that has a hydroxide concentration of #9.3*10^-16# M? Is this solution acidic or basic?

1 Answer
Apr 14, 2016

Answer:

You can determine it like this:

Explanation:

Assuming we have aqueous conditions, water dissociates:

#H_2O_((l))rightleftharpoonsH_((aq))^(+)+OH_((aq))^(-)#

#K_(w)=[H_((aq))^(+)][OH_((aq))^(-)]=10^(-14)"mol"^2."l"^(-2)# at #25^@"C"#

This means that #[OH_((aq))^(-)]=10^(-7)"mol/l"# from the ionisation of water.

An #OH_((aq))^(-)# concentration of #9.3xx10^(-16)"mol/l"# is vanishingly small in comparison so I would say that the solution is neither acid or alkali but neutral.