[Fractasm]

Hi everyone. I plan to use some muriatic acid to strip the deposits from sea shells and geodes. also I was going to try some acid etching in combination with hydrogen peroxide on copper jewelry. my question is what do I do with the excess muriatic acid and hydrogen peroxide/muriatic when I'm done with it? ive read that you can neutralize the Muriatic with baking soda but then what do I do with that? of course I don't want to throw it in the trash or down the drain. thanks for any feedback.

[kriggy]

If you neutralize HCl with baking soda you are left with solution of NaCl in water:
NaHCO₃ + HCl → NaCl + H₂CO₃
H₂CO₃ → H₂O + CO₂(g)

so you can throw it down the drain. Be careful however, neutralization is exothermic and CO₂ is evolved so add the soda slowly and use protective equipment.

[Fractasm]

what an awesome answer. I feel smarter just reading it. thanks so much. and I assume that I would just neutralize the muriatic/hydrogen peroxide mix the same way?

[Babcock_Hall]

Dilute and then neutralize it before pouring down the sink.  When you dilute, pour the acid into water, not the other way around.