+ Reply to Thread
Results 1 to 5 of 5

Thread: storing muriatic acid

  1. #1
    Michaela521 is offline ** No working email address ** Michaela521 0
    Join Date
    Apr 2006
    Posts
    14

    Default storing muriatic acid

    If you live in a very cold place like minnesota should you store muriatic acid in a heated place. It gets very cold where I am too.

  2. #2
    chem geek is offline PF Support Team Whibble Konker chem geek 4 stars chem geek 4 stars chem geek 4 stars chem geek 4 stars
    Join Date
    Nov 2004
    Location
    California
    Age
    55
    Posts
    2,187

    Default Re: storing muriatic acid

    The freezing point of Muriatic Acid (31.45% Hydrochloric Acid) is -46C (-50.8F) (for Hasa; other brands quote even lower freezing points) so unless you live in the Artic, I think you are safe to leave your Muriatic Acid outside.

    Richard
    Last edited by chem geek; 10-09-2006 at 04:42 PM.

  3. #3
    Join Date
    Dec 1969
    Location
    Ft Lauderdale, Fl
    Age
    52
    Posts
    1,382

    Default Re: storing muriatic acid

    Richard,

    How much difference does it lower the freezing point if you had a 4 parts water to 1 part muriatic solution in an outdoor tank? I would assume lower than water, but not quite into the negative temps...
    Sean Assam
    Commercial Product Sales Manager - AquaCal AutoPilot Inc. Mobile: 954-325-3859
    e-mail: sean@teamhorner.com --- www.autopilot.com - www.aquacal.com

  4. #4
    chem geek is offline PF Support Team Whibble Konker chem geek 4 stars chem geek 4 stars chem geek 4 stars chem geek 4 stars
    Join Date
    Nov 2004
    Location
    California
    Age
    55
    Posts
    2,187

    Default Re: storing muriatic acid

    Sean,

    The freezing point depression of water is -1.86C/m (3.35F/m) where "m" is molality or moles solute per kilogram of solvent (water) for a non-electrolyte (for an electrolyte such as HCl that dissociates into two parts, the depression is double this amount). So the amount of freezing point depression is solely a matter of the quantity (number of molecules; not weight) of substance dissolved in the water. So, if you dilute the Muriatic Acid (31.45% HCl) with 4 parts water, you dilute by 1/5th. The amount of freezing point depression will get reduced, but by more than 1/5th due the definition of molality.

    31.45% HCl means 31.45 grams of HCl in 100 grams of solution so that means 100-31.45 = 68.55 grams of water. HCl is 36.46 g/mole so the molality "m" is (31.45 g HCl / 36.46 g/mole HCl) / (68.55 grams water / 1000 grams/kilogram) = 12.58 m. So, 12.58 m * (-1.86C/m) * 2 = -46.8C which is about -46 as claimed by Hasa. Diluting the Muriatic Acid by 1/5th is done by volume, so Hasa says that the density of Muriatic Acid is 1.16 g/ml. The example of 100 grams of solution would be 116 ml in volume. You said you would dilute that by 4 parts of water so you would be adding 4*116 = 464 grams of water since pure water is about 1.00 g/ml. So now you would have the same 31.45 grams of HCl in 464+68.55=532.55 grams of water so that gives 1.62 m. So, 1.62 m * (-1.86C/m) * 2 = -6.0C (21.2F). So you are right that the new freezing point will be above 0F.

    [EDIT] This calculation was done backwards. 100 grams of Muriatic Acid solution would be 100/1.16 = 86.2 ml in volume. Diluting with 4 parts water would be 4*86.2 = 344.8 ml which is about 344.8 grams of water since pure water is about 1.00 g/ml. So now you have the same 31.45 grams of HCL in 344.8+68.55=413.4 grams of water so that gives 31.45/36.46/(413.4/1000) = 2.09 m. So 2.09 * (-1.86C/m) * 2 = -7.8C (18.0F). [END-EDIT]

    Richard
    Last edited by chem geek; 12-22-2007 at 05:54 PM. Reason: Corrected calculation (yes, it's tricky).

  5. #5
    Join Date
    Dec 1969
    Location
    Ft Lauderdale, Fl
    Age
    52
    Posts
    1,382

    Default Re: storing muriatic acid

    Geek, You ROCK. thanks
    Sean Assam
    Commercial Product Sales Manager - AquaCal AutoPilot Inc. Mobile: 954-325-3859
    e-mail: sean@teamhorner.com --- www.autopilot.com - www.aquacal.com

+ Reply to Thread

Similar Threads

  1. Can anyone tell me where to buy muriatic acid?
    By blessedbeingmom in forum Testing and Adjusting Pool Water Chemistry
    Replies: 6
    Last Post: 04-06-2011, 02:35 PM
  2. Lowering TA with Dry Acid Or Muriatic Acid
    By CelticDaddio in forum Dealing with Alkalinity and Calcium
    Replies: 30
    Last Post: 07-05-2007, 01:54 AM
  3. How Much Muriatic Acid?
    By TfromNC in forum Pool Chemicals & Pool Water Problems
    Replies: 4
    Last Post: 06-27-2006, 07:32 PM
  4. How to add muriatic acid
    By BullDean in forum Pool Chemicals & Pool Water Problems
    Replies: 5
    Last Post: 06-12-2006, 11:51 PM
  5. how much muriatic acid
    By wolfcue in forum Dealing with Alkalinity and Calcium
    Replies: 10
    Last Post: 06-07-2006, 06:55 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts