1) How would you prepare 20 mL of a solution having pH = 2.00 by dilution of 0.10 M HCl?

2) The Ka, for hypochlorous acid, HClO, is 7.2 x l0^–4 at 25°C. What is pKa? Write the equation for the reaction to which Ka applies.

final concentration=10^-2 from pH=2

final concentration=.01M
so you want to dilute it 10 x, or 9 parts water, one part stock.

So add 2ml of the .1M to 18ml water, stir, label, and store.

2. pKa=-logKa

HClO>>>H+ + ClO-