[MarineMedic]

Was soaking something in H2O2.  Second party, without my knowledge and trying to help, added equal part of Cl.  Well, the resultant solution not only cleaned my little item, it ate it.  I'm figuring we made a solution of hydrochloric acid.  Is that in fact what it was?

[nj_bartel]

Need to know exactly what happened.  You're being incredibly vague.

[Borek]

You can't add just Cl.

[Arkcon]

Concentrated acids, either hydrochloric acid or sulfuric, mixed with strong (30%) hydrogen peroxide solutions are commonly called Piranha solutions.  Such mixes are good for thoroughly cleaning organic soils off glass, or metal surfaces, for such applications such as electronic circuit building, cell adhesion, etc.

Briefly, where I come from, we label our reaction vessels with contents -- all reactants, the date, and the initials of the operator.  And we fire people who just add a dash of sumthin' to sumthin' to "help."

Try and give us a complete explanation of what you were doing, if you need more help.