Turning ammonia into ammonia hydroxide?

[samz90]

Turning ammonia into ammonia hydroxide. how do you do it?

thanks

[j2buttonsw]

If you bubble ammonia gas through water you get an ammonium hydroxide solution, don't you?

NH3 (g) + H2O (l) <--> NH4OH (l)

[shammydodger]

Here's a detailed preparation:

Ammonium hydroxide is the old name for solutions of ammonia dissolved in water. There is actually no such compound as ammonium hydroxide, but by convention that is what it is called. The best means of storing ammonia in an improvised lab is by dissolving it into water. Water can hold a considerable volume of ammonia at lower temperatures. At room temperature a 31% ammonia solution can be had, at 0 degrees C the concentration can be up to 47%. Commercially ammonia solutions are between 20-30%.

To prepare a highly concentrated ammonium hydroxide solution set up a series of bottles filled with water. Place a long and short length of glass tube into a two-hole stopper affixed to the bottles. The long end can have a bubbler attached to it to improve the solubility of ammonia. The short length of tube should not go under the surface of the water. The bottles should be connected with plastic or rubber tubing with the short tube of one bottle attached to the long tube of another. In this manner the ammonia gas will be bubbled into the first bottle, any excess will pass into the next bottle, and so on. This setup will help to minimize any waste of ammonia. At the bare minimum one can stick a length of tubing into a bucket of water.

The ammonia source can be either the solid or aqueous preparations above, or from a weaker ammonium hydroxide solution. As previously mentioned it is more difficult to do this with weak solutions such as grocery store ammonium hydroxide. The ammonia generator is connected to the first bottle in the series and the reaction is commenced.

The longer this reaction is conducted the more bottles that will be needed. Eventually the first bottle will become completely saturated, while the secondary bottles will have decreasing concentrations. Cooling the water bottles, or more appropriately only the first bottle can increase the maximum concentration.

[Science man]

I think that if you put it in water it turns to a hydroxide

[Science man]

you put it in water and collect what's left

[brachiopod]

Ammonia gas is highly soluble in water, forming 'ammonium hydroxide' (aq)

- god I feel old saying this, but I have to say "I remember doing this at school" - look up the 'fountain experiment' on google (add 'ammonia' as a key word)

I must add, that I have experience as a lab technician in secondary education, and this (and all the other fun experiments) are strictly "Demonstration Only" these days. Pah!!

[brachiopod]

I hadn't even tried googling myself when I suggested the above, but the very first site if you put in;

ammonia "fountain experiment"

you get this site, which even has a great little vid of the experiment.

(Sorry kids, it's only adults that can play... er-hum, I mean DEMONSTRATE these experiments these days. And if you really want to know how this (or any other experiment) really works - ask your Science Technician, as they've probably spent the last two hours before your lesson started, explaining to the teacher what is going on !!

[shammydodger]

I recall my chemistry teacher demonstrating the Thermit reaction, which had a practical application in the welding of railway track. These days, it would probably require an Act of Parliament and a 400-yards exclusion zone to approve such a demo!

And we wonder why chemistry is dying a slow death in universities!