As I went to do an A/O this morning, it became evident that I'd run myself
out of Phosphoric acid.

Can I use a comparable concentration of sulfuric acid as a substitute?

TIA,

clyde

Clyde Gill wrote:
> As I went to do an A/O this morning, it became evident that I'd run myself
> out of Phosphoric acid.
>
> Can I use a comparable concentration of sulfuric acid as a substitute?
>
> TIA,
>
> clyde
Clyde,

I'm not sure what you mean by an A/O, but if it's some kind of acid
titration, you've got to take into account that phosphoric, H3PO4, has
50% more H+ ions per mole than sulfuric, H2SO4. Sorry I can't be of more
help.

--


Mike MTM, Cokesbury, New Jersey, USA

MikeMTM ) wrote:
>Clyde Gill wrote:
>> As I went to do an A/O this morning, it became evident that I'd run myself
>> out of Phosphoric acid.
>>
>> Can I use a comparable concentration of sulfuric acid as a substitute?
>>
>> TIA,
>>
>> clyde
>Clyde,

>I'm not sure what you mean by an A/O, but if it's some kind of acid
>titration, you've got to take into account that phosphoric, H3PO4, has
>50% more H+ ions per mole than sulfuric, H2SO4. Sorry I can't be of more
>help.

>--


>Mike MTM, Cokesbury, New Jersey, USA



Hi Mike,.

I think he means the aeration/oxidation reaction to measure free
SO2. The acid just serves to put the pH of the wine below 1.0, so
that all the SO2 in solution exists as molecular SO2 rather than
HS03-.

I've thought about using sulfuric acid, but I wasn't sure if you
would blow over something that would look like, or react like
sulfuric acid in your hydrogen peroxide. Sulfuric acid is ultimately
what you're titrating for to meausre SO2.

Dave
************************************************** **************************
Dave Breeden

David C Breeden wrote:
>
> Hi Mike,.
(snip) I've thought about using sulfuric acid, but I wasn't sure if you
> would blow over something that would look like, or react like
> sulfuric acid in your hydrogen peroxide. Sulfuric acid is ultimately
> what you're titrating for to meausre SO2.
>
> Dave
> ************************************************** **************************
> Dave Breeden

Dave,

Ah, I learn something every day. Thanks.

I suspect you're right: that the common ion effect might interfere a bit
with the ultimate rxn, but a rough result could probably be obtained, if
that was adequate. I'd want to double check for peace of mind though.
--


Mike MTM, Cokesbury, New Jersey, USA

Clyde I am rather puzzled as to what you intend adding Phosphoric acid too.
unless
Soft drink manufacturers use phosphoric acid in some of their products to
provide a pleasant tartness.

Sulfuric Acid
Product Type: Liquid
Also known as oil of vitriol or dripping acid, it is the most important and
widely used industrial acid.
It is used in the manufacture of inorganic and organic acids, electronics,
batteries, neutralization,
synthetic drugs, technical gasses; an important laboratory reagent; a
nitrating, sulfonating,
pickling and drying agent; used in preparing soluble phosphates.

Stephen SG
------------------
"Clyde Gill" > wrote in message
om...
| As I went to do an A/O this morning, it became evident that I'd run myself
| out of Phosphoric acid.
|
| Can I use a comparable concentration of sulfuric acid as a substitute?
|
| TIA,
|
| clyde

"Clyde Gill" > wrote in message
om...
> As I went to do an A/O this morning, it became evident that I'd run myself
> out of Phosphoric acid.
>
> Can I use a comparable concentration of sulfuric acid as a substitute?

Hi, Clyde -

Yes, I'm pretty sure that's OK. All you're doing is bringing down the pH so
the free sulfite all becomes molecular free SO2 and you can drive it off
with a gas stream into H2O2. The actual amount of phosphoric or sulfuric
isn't critical - just as long as it's in excess.

I noticed that Titrets use phosphoric acid for their reverse Ripper
analysis. I've always used 25% sulfuric when running a Ripper. I suspect
they're interchangeable, with the sulfuric being cheaper but the phosphoric
being safer to handle.

Tom S

> Hi, Clyde -
>
> Yes, I'm pretty sure that's OK. All you're doing is bringing down the pH


Thanx all for the responses. As usual,
I was cutting it to the wire, so here's
a rundown of how it went.

I checked the pH of the little bit of
25% phosphoric on hand, and it was 0.50 pH.
So then I went about making a suitable
concentration of sulfuric, which came out
to 0.60 pH at 5%. I just used slightly more
of this mixture to compensate for the higher
pH, but that was probably overkill.

It seemed to work out fine. I tested
this against a ripper and the results
were consistant. Was testing three
barrels of red (pH of 3.45) which were tested,
adjusted, and topped 3 months ago. For
the record, these wines were all in the
35-38 ppm range and were bumped up by 15 ppm
for bottling. We bottled the blend of the
three yesterday, so I was desperate for an
accurate reading.

Thanx again everyone for responding. I'm
assuming that the misunderstandings/questions
about what I was doing have been cleared up
through the rest of the thread, but if anyone
has any other questions or comments...

clyde
Steelville, Missouri, USofA
http://www.PeacefulBend.com
http://www.vinic.com

"Clyde Gill" > wrote in message
om...
> Thanx again everyone for responding.

No thanks required. A few bottles of whatever that was you bottled will
cover the consulting fee. ;^D

I hope it was Norton...

Tom S