How to produce anhydrous HCl gas using no special equipment

by Psychokitty

To date I have never used Strike's and Fester's method for producing HCl gas. Reasons for this are as follows:

  1. The necessity of laboratory glassware (no OTC hardware).
  2. What seems to be a messy procedure using table salt (but I wouldn't know exactly as I've never tried it).
  3. Difficult dismantling process (at least it seems to be more difficult than mine).

I don't remember the exact journal reference that inspired my method, but I do know that it is described somewhere in Inorganic Syntheses Vol. I.

Okay. First, here is what you need:

  1. Beer bottle (transparant).
  2. Plastic baby syringe (15 ml capacity) found at the pharmacy section at any grocery store.
  3. Four or so feet of ice-maker transparant-white polyethylene tubing found at the hardware store. (I don't remember the exact diameter size. All I know is that it IS the smallest size available.)
  4. One table-leg stopper (rubber, beige or black). Another item of which I don't know the size. Just take your beer bottle into the hardware store and see which size fits snuggly on its top.
  5. One aluminum tube that is the exact diameter size as the polyethylene tubing. Found at the hardware store but don't know what they are used for. They are sometimes made of brass.
  6. One bottle of sulfuric acid drain cleaner.
  7. One bottle of concentrated hardware store muriatic acid (32%?)

Assembling the HCl generator is easy.

  1. Use the aluminum tubing to burrow two holes to the top of the table-leg stopper. Use a twisting motion while appling pressure for about a minute and eventually the tube will pop through.
  2. Place the table-top stopper over the top of the beer bottle. It'll fit snugly.
  3. Insert the polyethylene tubing into the middle-most hole and push through until the tubing hits the bottom of the beer bottle. With scissors or a knife cut off the polyethylene tubing about two inches from the top of the beer bottle.
  4. Take the entire table-top stopper inserted with the polyethylene tubing off of the beer bottle. Pour into the beer bottle a volume of sulfuric acid about an inch high off of the bottom of the beer bottle.
  5. Replace the table-top stopper/polyethylene tubing on top of the beer bottle. Insert the remaining tubing into the last hole of the stopper until about two inches into the bottle. Cut tubing down to desired length.
  6. Pour about twenty milliliters of concentrated HCl into a cup. Extract into baby syringe until syringe is full (15 mL). NO, the HCl will not dissolve any part of the syringe in any way.

    Neither the HCl nor the strong sulfuric acid will react with any piece of hardware used in this system. This setup has been tested many times with success.

  7. Insert the syringe into the middle tubing (the one that extends to the bottom of the beer bottle. End should be submerged in Sulfuric acid.) If insertion is difficult, use a knife to scrape the inside of the tubing to allow the syringe to fit more easily.
  8. Securing the set-up with a clamp of some sort attached to a stand is optional but desirable.
  9. Have handy on the side a container full of water.

The use of this set-up to gas ones solvent/amine is just as easy.

  1. With right hand, hold the tubing that will expel gas and lower into the solvent/amine solution.
  2. With left hand slowly start to inject the HCl solution in the syringe into the sulfuric acid. Once it hits the acid, there will be alot of fizzing and foaming and IMMEDIATELY HCl gas will be pumped into the solvent/amine solution. Foaming is sometimes a problem as it starts to reach the top of the beer bottle. Simple wait a while and let it settle and then continue. Sometimes certain brands of drain opener can cause excessive foaming. If this occurs, switch brands.
  3. One syringe is usually enough for an amount of about 30-40 g of product, but if more is needed after all the HCl has been injected, slowly SLOWLY remove the syringe from the tubing, first be letting a crack of air into the system. BEWARE that this is suddenly going to bring a minor rush of HCl from the gassing tube so make sure that it is submerged when doing this step. To continue, refill the syringe and proceed as described above.
  4. Once the gassing is complete, leave the syringe ATTACHED to the injection tube and submerge the gassing tube in the container full of water (If the syringe is not attached to the injecting tube, the following sequence will not occur). Weigh down the gassing tube somehow as it must remain submerged. In a few minutes (about five) the sulfuric acid will cool a bit causing a sucking-back of the water into the beer-bottle. This will happen very suddenly and very fast, but not to worry as the water will only go in as far as the top of the beer bottle. This is actually an advantage as in this way one is able to dilute the remaining HCl gas AND the remaining sulfuric acid. Of course the bottle will get hot but if left aside for a few minutes it will eventually cool making opening the container and dispensing with the acid solution an easy task. If the bottle is opened for whatever reason without the above acid dilution step, HCl gas will be everywhere.

Hope this method will prove useful to you my fellow bees, it sure has been for me!