Re: [Fwd: Re: [CH] news item: El Paso Pepper Producer (chipotles)]

Love2Troll (Love2Troll@kc.rr.com)
Mon, 5 Apr 2004 18:54:06 -0500 

> It would be interesting if someone with a pH meter could
check this -- 

I didn't take the time to calibrate either of the meters with buffer solutions, but one read 4.9 and the other 5.18 on a 3% solution that doesn't state if % by volume or by weight.
  ----- Original Message ----- 
  From: T. Matthew Evans 
  To: AndyB ; Chile Heads 
  Sent: Monday, April 05, 2004 6:22 PM
  Subject: Re: [Fwd: Re: [CH] news item: El Paso Pepper Producer (chipotles)]


  Peter and AndyB --

  Actually, I don't think that the article is referring to hydrogen peroxide
  being mixed with another acid -- otherwise, I don't think that they would refer
  to it as "peroxide acid".  Here's my thought -- when hydrogen peroxide (a thick
  syrupy liquid) is mixed with water (like the hydrogen peroxide you buy at the
  drugstore), it forms a weak acid.

  Hydrogen peroxide has a dissociation constant (Ka1) of about 2.4e-12, meaning
  that when mixed with water, it loses some of its hydrogen ions.  These stray
  hydrogens lower the pH of the mixture (remember, pH = -log[H+]) and viola,
  you've got a weak acid.  I just did some "back of the envelope" calculations,
  and I think that the pH of store-bought hydrogen peroxide should be about 5.8
  -- less than seven.  It would be interesting if someone with a pH meter could
  check this -- my number should not be exact because I don't know the actual
  process used to make the peroxide (e.g., 3% by mass or by volume?) and I did
  not take into account vapor equilibrium (i.e., there is a constant exchange of
  chemicals across the free surface of the peroxide).

  Remember, I'm not really a dilute solution chemist, I just play one on the
  Internet.

  Matt

  --- AndyB <barnhart@mfire.com> wrote:
  > 
  > 
  > -------- Original Message --------
  > Subject: Re: [CH] news item: El Paso Pepper Producer (chipotles)
  > Date: Mon, 05 Apr 2004 17:30:13 -0400
  > From: AndyB <barnhart@mfire.com>
  > To: Peter G <peter.g@telus.net>
  > References: <40704338.6070700@telus.net>
  > 
  > Peter,
  > 
  > Hydrogen peroxide is a common oxidizer/antiseptic.  In some circumstance,
  > it can be combined with an appropriate acid for both cleansing and
  > sterilization purposes.  E.g., see
  > 
  >    http://www.megaconcentrate.com/cipcleaners.htm  - "CIP acid"
  > 
  > AndyB
  > 
  > Peter G wrote:
  > 
  > > Hi Folks,
  > > 
  > > here's an interesting news item ran across while searching for things 
  > > fungal .
  > > 
  > >    Red-Hot Ideas: El Paso Pepper Producer
  > >
  >
  http://www.newspapertree.com/newsletter.ssd?section=feature&c=712434d153474098
  > 
  > > 
  > > 
  > > any chemists out there who can explain whatever they're calling 
  > > "peroxide acid"
  > > might be? any contraindications?
  > > 
  > > regards
  > > peter g
  > > 
  > > 
  > > 
  > > .
  > > 
  > 
  > 
  > 
  > 


  =====


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