Help with Concentration from pH?

What is the hydronium ion concentration of an aqueous solution with a pH of 9.50?

Please explain. Thank you for your knowledge.

1 Answer
Mar 3, 2018

#10^(-19/2)"M"#

Explanation:

We know that the formula for #"pH"# is:

#"pH"=-log["H"_3"O"^+]#.

Here, we have that #"pH"=9.5#. Inputting:

#9.5=-log["H"_3"O"^+]#

#log["H"_3"O"^+]=-9.5#

So, as #loga=x# means that #10^x=a#, we can write:

#10^(-9.5)=["H"_3"O"^+]#

#["H"_3"O"^+]=10^(-19/2)"M"#

The answer.