Dilution calculations help - Home Brew Forums

 Home Brew Forums > Dilution calculations help

03-13-2009, 07:05 PM   #1
GilaMinumBeer
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I am looking at a product,

128 Ounces (1 Gallon) of 46% Phosphoric Acid.

The suggested dilution is at 2 Gallons or 6 Gallons. My challenge here is to determine the percentage of PA at dilution. How do I calculate this to the suggested dilution (assuming neutral water used)?

03-13-2009, 07:18 PM   #2
Loweface

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Not sure what you're looking for?

1 gallon 46% Phosphoric Acid + 1 Gallon Water = 2 Gallons 23% Phosphoric Acid
1 gallon 46% Phosphoric Acid + 5 Gallon Water = 6 Gallons 7.6% Phosphoric Acid

Is that what you were looking for?

What concentration are you looking for?
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03-13-2009, 07:19 PM   #3
GilaMinumBeer
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Doh. Sorry.

The suggested dilutions are 1 ounce per 2 gallons or, 1 ounce per 6 gallons.

03-13-2009, 07:24 PM   #4
Loweface

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Ok I'll get back once I convert to metric...

Edit:

If my converstion is right

1oz in 2 gallons is 0.18% Phosphoric Acid
1oz in 6 gallons is 0.06% Phosphoric Acid
__________________
Quote:
 Originally Posted by Me In the process of buying a bar... One drink at a time...
Quote:
 Originally Posted by chortly ...homebrew contains more satisfactrons per serving, so you don't have to drink as much as you would a commercial beer to get to your satisfactron saturation.

03-13-2009, 07:33 PM   #5
GilaMinumBeer
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Thanks. I am blundering my way to the same numbers.

03-13-2009, 10:18 PM   #6
ghostbrewer

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Mar 2009
Virginia Beach
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Quote:
 Originally Posted by Loweface Not sure what you're looking for? 1 gallon 46% Phosphoric Acid + 1 Gallon Water = 2 Gallons 23% Phosphoric Acid 1 gallon 46% Phosphoric Acid + 5 Gallon Water = 6 Gallons 7.6% Phosphoric Acid Is that what you were looking for? What concentration are you looking for?

Here is a generic solution:

(Vi ) x (%i ) = (Vf ) x (%f )
where Vf = Vi + Vdilution
Vf = final volume
Vi = initial volume of phosphoric acid used
%i = percent phosphoric acid in initial volume
%f = percent phosphoric acid after dilution
Vdilution = volume of water added

Always add acid to water. This will work regardless of units (metric or Brittish)

03-14-2009, 12:17 AM   #7
menschmaschine

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Delaware
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Quote:
 Originally Posted by LASTNHOVGATOR Here is a generic solution: (Vi ) x (%i ) = (Vf ) x (%f ) where Vf = Vi + Vdilution Vf = final volume Vi = initial volume of phosphoric acid used %i = percent phosphoric acid in initial volume %f = percent phosphoric acid after dilution Vdilution = volume of water added
This is the same as C1V1 = C2V2
C = Concentration
V = Volume

So:

46 X 1 = C2 X 257 (for 1 oz. per 2 gallon)
C = .18%

Loweface already got it, but I thought it was worth posting the equation because it is very valuable in brewing.
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03-14-2009, 09:50 PM   #8
Loweface

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That's esentially how I did it I just don't know how many oz in a gallon
__________________
Quote:
 Originally Posted by Me In the process of buying a bar... One drink at a time...
Quote:
 Originally Posted by chortly ...homebrew contains more satisfactrons per serving, so you don't have to drink as much as you would a commercial beer to get to your satisfactron saturation.

03-16-2009, 10:23 AM   #9
Scientist83
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West Chester, PA
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Yes always, add Acid to Water!! I can't stress that enough. Adding acids to H20 causes a rapid shift in pH. While you're only working with a small concentrations, it also causes exothermic reactions to occur (i.e....the temp. of the solution increases as well). It's not mandatory, but it's a safety thing. Good Advice LASTNHOVGATOR.

03-16-2009, 07:30 PM   #10
SumnerH
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Alexandria, VA, USA
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Quote:
 That's esentially how I did it I just don't know how many oz in a gallon
Welcome to the American system of weights and measures.

1 pint = 16 oz is common knowledge for beer drinkers (a regular bottle of beer is 12oz)

2 cups = 1 pint
2 pints = 1 quart
4 quarts = 1 gallon

Easy-ish to remember: 2 except the quart is short for quarter so there's 4 of them in the next size.

Now, with smaller volume measure it gets weird ( 3 teaspoons = 1 tablespoon, 16 tablespoons = 1 cup).

And the British system is different. A British pint is 20 oz. From there it's still 2 pints in a quart, 4 quarts in a gallon, so a British quart or gallon is obviously bigger than an American quart or gallon.
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