[fran008]

Pb(OH)2 reacts wirh dilute HCl in what way? Does it form PbCl2 and H20?

[lemonoman]

Well, if Ph(OH)2 is soluble in water to any measurable degree (refer to solubility constant) then the Pb2+ ions will definitely be dissociated from the OH- ions.  And if you add H+ ions from a dilute hydrochloric acid solution, you're increasing H+ in a solution which ALREADY has elevated OH- content

And remember that Kw = [H+][OH-] = 10^-14...the product of those two concentrations can't exceed that number.  The concentration in your case HAVE to decrease somehow...and the acid/base reaction you suggested is an ideal way to do that.