Posted by Curtis on .
A buffer solution contains 0.283 M hypochlorous acid and 0.456 M potassium hypochlorite.
If 0.0464 moles of perchloric acid are added to 225 ml of this buffer, what is the pH of the resulting solution ?
(Assume that the volume change does not change upon adding perchloric acid)
pH =

chemistry 
DrBob222,
millimols HOCl = mL x M = 225 x 0.283 = estimated 64.
mmols KOCl = 225 x 0.456 = 103
add 46 mmols HClO4.
..........OCl^ + H^+ ==> HOCl + H2O
I.........64......0........103
add..............46.............
C........46....46.........+46
E.........18......0........149
Substitute the E line into the HendersonHasselbalch equation and solve for pH. You will need to look up or calculate pKa for HOCl
Note that I have rounded on all of the numbers. You will need to recalculate and obtain more accurate numbers.