Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: The Scientist on 01/07/2010 13:58:52

Title: How can I tell if an acid is strong enough to destroy metals?
Post by: The Scientist on 01/07/2010 13:58:52
When I refer to metal I mean metals in general. 'Everyday' metals. Please answer the question as detailed as possible. According to my knowledge, Acids work through metals while alkaines work through non-metals. Please correct me if I am wrong. Thank you!
Title: How can I tell if an acid is strong enough to destroy metals?
Post by: Bored chemist on 01/07/2010 19:13:07
How fast?
What metals? Copper, zinc lead and iron are all fairly common, but they differ considerably in their resistance to acids (and some will resist some acids better than others.
Also, I'm afraid you are wrong, (some) alkalis will attack some metals and (some) acids will attack some non metals
Title: How can I tell if an acid is strong enough to destroy metals?
Post by: tommya300 on 02/07/2010 05:10:53
Hydrofluoric Acid eats through glass, diluted it is a great window cleaner
Title: How can I tell if an acid is strong enough to destroy metals?
Post by: Bill.D.Katt. on 02/07/2010 18:06:52
When you say how "strong" an acid is there are usually two things to consider: pH, and oxidizing capabilities. HCl is strong, but will not eat through Cu because it has no oxidizing capabilities. HNO3 on the other hand... You can add an oxidizer to HCl or even HC2H3O2 to make a "poor mans aqua regia," H2O2 works well. Usually the higher the electronegativity of a metal, the more likely you will need an acid with strong oxidizing capabilities.
Title: How can I tell if an acid is strong enough to destroy metals?
Post by: lightarrow on 02/07/2010 20:00:14
Quote from: The Scientist on 01/07/2010 13:58:52
When I refer to metal I mean metals in general. 'Everyday' metals. Please answer the question as detailed as possible. According to my knowledge, Acids work through metals while alkaines work through non-metals. Please correct me if I am wrong. Thank you!
You are wrong. Counter-examples:
1. If HNO3 is diluted, it will dissolve iron, if concentrated it'll do nothing to it.
2. Concentrated H2SO4 is much stronger than diluted HF but the first does nothing to aluminum, the second dissolves it easily.