DaveC <
davec2468@...> writes:
> I'm confused: you use LESS hcl and the reaction was faster? I thought
> the acid is what increased (using more) or decreased (using less) the
> speed of the reaction, no?
Reactions run fastest when all the parts needed are present in
sufficient quantities. Pure HCl will ∗not∗ etch copper! You also need
an oxidant! (amusingly enough, pure HCL ∗will∗ take the tarnish off
copper, as the tarnish is pre-oxidized copper) The H2O2 provides an
oxidant, so you need enough of that also. In a CuCl etchant, the CuCl
is itself an oxidizer and acid, but you still need HCl to provide
additional Cl atoms for it to work.