The pH of a solution is 5.6. What are the hydrogen and hydroxide concentrations?

1 Answer
May 13, 2016

#pH =-log[H_3O^+]#

#[H_3O^+]*[OH^-]=10^-14#

Explanation:

The pH of a given solution is determined using the following formula:

#pH =-log[H_3O^+]#

To find the #[H_3O^+]# the formula must be manipulated as follows:

#log[H_3O^+]= -pH#

#[H_3O^+]=10^(-pH)#

Plugging the value of the pH in the equation gives:

#[H_3O^+]=10^-5.6#

#[H_3O^+]=10^0.4*10^(-6)#

#[H_3O^+]=2.51*10^-6 M#

In an aqueous solution,

#[H_3O^+]*[OH^-]=10^-14#

#[OH^-]=(10^-14)/([H_3O^+])#

#[OH^-]=(10^-14)/(2.51*10^-6) =3.98*10^-9 M#