Prussic acid-- cyanide?

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

ddnoe@bellsouth.net - 20 Sep 2007 17:07 GMT

I asked a pharmacist about prussic acid and the pharmacist didn't even
recognize the term. Can someone tell me if prussic acid is the same
substance as cyanide?
If so, when and why did cyanide replace the term prussic acid?
Thanks to anyone who can help.

Reply to this Message

Kay Lancaster - 21 Sep 2007 03:42 GMT

> I asked a pharmacist about prussic acid and the pharmacist didn't even
> recognize the term. Can someone tell me if prussic acid is the same
> substance as cyanide?

As I learned it back in chemistry a jillion years ago, prussic acid is
hydrogen cyanide, HCN. There are a lot of other cyanides (the cyanide
ion is CN-) like sodium cyanide, potassium cyanide.

> If so, when and why did cyanide replace the term prussic acid?

I suspect that prussic acid is derived from the pigment "Prussian blue",
ferric ferrocyanide. HCN was synthesized about 70 years after
Prussian blue, which, iirc, was about 1710.

"Prussic acid" is still often seen in agronomic references talking about
forage crops with cyanogenic glycosides, but I don't recall any chemist
talking about prussic acid unless they were dealing with cyanogenic
glycosides. Just one of those historic names that are still hanging
around in unswept corners, I guess.

Kay

Reply to this Message

ddnoe@bellsouth.net - 21 Sep 2007 10:27 GMT

> > I asked a pharmacist about prussic acid and the pharmacist didn't even
> > recognize the term. Can someone tell me if prussic acid is the same
[quoted text clipped - 3 lines]
> hydrogen cyanide, HCN. There are a lot of other cyanides (the cyanide
> ion is CN-) like sodium cyanide, potassium cyanide.

(Denise) When people in common parlance refer to "cyanide," which
cyanide are they referring to? Could they be referring to any of
them? Are they all poisons?

> > If so, when and why did cyanide replace the term prussic acid?
>
[quoted text clipped - 9 lines]
>
> Kay

(Denise) Kay, may I quote you for publication? If so, how do I
identify you? Are you a pharmacist or what?
Thank you.

Reply to this Message