Concentrated fuming

There are some alternatives to this HCI generator type of crystallization. There are, of course, canisters of HCI gas that can be purchased. Also, one can crystallize with very concentrated (fuming) HCI by pouring the stuff directly into the ether/freebase [26]. Regular 35% HCI can do this too, but the water content may dissolve the MDA.HCl or make the crystals sticky which means that the chemist will have to dry the solution by removing the water. 

Dilute nitric acid or sulfuric acid in place of concentrated fuming nitric acid or oleum (SO3 solution in sulfuric acid)... 

Dilute nitric acid instead of concentrated fuming nitric acid — Wet benzoyl peroxide instead of dry... 

Hydrochloric acid (concentrated, fuming ). The commercial concentrated hydrochloric acid is a water-like solution with a characteristic smell, and is fuming owing to the evaporation of hydrogen chloride gas. It has a density of 1 19 g cm 3, contains 36 0 % (w/w) HC1 (or 0 426 g HC1 per ml), and is approximately 11 7 molar. The reagent should be stored far away from concentrated ammonia to prevent the formation of ammonium chloride fumes. It should be handled with care, using eye protection. 

Other substances. The concentrations of acids and bases and alkalis could be listed as follows acetic acid > 25% concentration, hydrochloric acid > 25% concentration, nitric acid > 20% concentration, chromic acid, hydrofluoric acid, perchloric acid > 10% concentration, sulfuric acid > 15% concentration, fuming sulfuric acid, ammonium hydroxide > 35% by weight of gas, potassium hydroxide (caustic potash), sodium hydroxide > 5% concentration, aluminum chloride, bromine, phosphorous trichloride, potassium bifluoride, sodium hypochlorite > 10% concentration, and zinc chloride. 

For production of monosulphonic acid a somewhat concentrated fuming sulphuric acid (containing 30 to 40 per cent, anhydride) is required, and the sulphonation should take place at as low a temperature as possible. 

Hazard Inhalation of concentrated fumes may be fatal. TLV 25 ppm. Moderate fire risk, explosive limits in air 16 to 25%. Forms explosive compounds in contact with silver or mercury. 

Highly toxic. Inhalation of concentrated fumes may cause death. Irritates eyes and skin. 

Precautions Breathing of concentrated fumes may be fatal. Explosive compounds form in contact with silver or mercury. 

Ammonia (NH3) reacts with iodine to give nitrogen triiodide, which detonates on touch. Ammonia reacts with hypochlorites to give chlorine. Mixtures of NH3 and organic halides sometimes react violently when heated under pressure. Ammonia is combustible. Inhalation of concentrated fumes can be fatal. 

That means that any bottle of sulfuric acid will have some SO3 in it. At room temperature, SO3 is a gas, and it is possible to add extra SO3 gas to sulfuric acid (which shifts the equilibrium). When we do this, we call the mixturesulfuric acid. So, from now on, whenever you see concentrated, fuming sulfuric acid, you should realize that we are talking about SO3 as the reagent. 

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