[quote=@Earnest Evans]
Diluted sulfuric acid is not really acidic. If you want to have your character's acidic powers be strong enough to have a noticeable effect within seconds or minutes instead of [i]hours[/i], I'd recommend having a concentration around industrial sulfuric acid at most, since that's the closest to the Hollywood "melt paint off steel" acid you seem to be looking for. 

The molarity of a liter of sulfuric acid is around 18 mol/L. However, sulfuric acid can be washed off somewhat easily and is largely halted by glass or plastic. Potentially, you could extend that to magical shields. It'll be reasonably effective against metals, immensely effective against electronics and bare skin, and almost useless against glass and magic shields.

If you want to be as acidic as a bath of acid-water, that's entirely up to you.
[/quote]

Thing is. She's not a liquid. She's a slime. Not so easily washed up. I also don't want to be really over-powered. I'll take your advice and go with the industrial sulfuric acid then.