William Robb wrote:
>Anyway, the only time I take any sort of precautions, other than
>common sense, with chemistry is when I am working with the
>stuff....
>I don't wear protective gear with the stock solution,
>just the full strength acid.
>For that, I wear a neoprene apron, neoprene gloves, goggles and
>an ammonia mask.
Not a bad approach, Bill. Especially the part about the eye protection.
Haven't seen it mentioned here yet, but another good practice when making
dilutions of any concentrated acids is to add the acid to the water, rather
than doing the reverse. The reason is that concentrated acids are generally
quite hygroscopic (they readily absorb moisture), and mixing of acids and
water can often generate a lot of heat. If you add a little concentrated
acid to a lot of water, you don't generate much heat. OTOH, if you add a
little water to a lot of concentrated acid, you can generate considerable
energy -- often enough to cause the acid solution to spatter onto clothing,
skin, etc. Definitely a concern with mineral acids like nitric, sulfuric,
or hydrochloric. Can't remember if glacial acetic acid represents as much
of a concern (and I probably should be able to remember this), but the
acid-to-water rule is certainly a prudent one to follow.
Bill Peifer
Rochester, NY
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