Does car-battery acid evaporate?

Say there’s a puddle of it on a garage floor. Would it evaporate? How quickly?

Battery acid is a mixture of sulfuric acid and water. The water evaporates; the sulfuric acid doesn’t. You might sprinkle baking soda on the acid to neutralize it.

Thanks - but haven’t people been injured before by inhaling sulfuric acid fumes?

many people have been killed, blinded, scarred, maimed and otherwise damaged by sulfuric acid. including a few of my friends during my time in refineries :mad:

… however probably not so many bad injuries from a small pool of spilt battery acid. You wouldn’t want to drink it, nor would you want to let the water evap and then get the powder onto any mucous membrane.

basic precautions including gloves, eye protection and a healthy dose of common sense should mean you are perfectly safe to clean it up. I assume thats what your question relates to.

But if there’s such a thing as sulfuric acid fumes, then it must evaporate.

sulfuric acid won’t evaporate, but is hygroscopic and will draw water from the air. It won’t ‘turn to powder’ 98-99% H2SO4 that is readily purchased is in a liquid form. I think it will gradually release oxides of sulfur fumes (SO3), especially when heated, but these fumes will combine with water (like in your eyes and nose) and become acid again.

It won’t just go away. It will corrode whatever it can and turn to sulfates; or it will sit there collecting water turning to a bigger puddle of vile. Its better to ventilate well and add a neutralizing agent like baking soda

Right - that’s my question - how people inhale fumes if it doesn’t evaporate.

I think “decompose and outgas SO3” is probably more accurate rather than evaporate. But the rate is pretty slow and will take quite a long time unless it is heated up. Plus there is the problem that these fumes will land on something eventually and pretty much destroy that as well. It will attract water at a faster rate; so while it will become somewhat more dilute, you will have a bigger puddle of terribly nasty stuff that is only slightly less destructive than the more concentrated stuff.

Its not going to evaporate and disappear anytime soon. Its smarter to neutralize it and contain it in the liquid state rather than have the hinges fall off your doors.