Question #702d7

1 Answer
Oct 27, 2016

Using the formula for #"pH"#, #"pH" = -log["H"^+]#

Explanation:

We also have to work out the molarity of the aqueous acid.

Let's look at an example:

Calculate the #"pH"# of a #0.0025# #"M"# #"HCl"# solution.

#"HCl" ("aq") + "H"_2"O" ("l") rarr "H"_3"O"^+ + "Cl"^-#

#"HCl" # is a strong acid and is #100%# ionised in water. Thus, the hydronium ion concentration is #0.0025 "M"#.

#"pH" = - log (0.0025) = - ( - 2.60) = 2.60#