What exactly is NH4+?

[Feline]

Ok, so I don't have much knowledge on chemistry. But I have the following question to ask:

Pure ammonia = NH3
But what is NH4+? (which is said on the manual of the test kit for ammonia)

And why ammonium hydroxide (when ammonia is combined with water) is called NH4OH instead of NH5O?

 

[canis_lupus]

k i've probably got this all wrong but here we go NH4+ is an ion of ammonia also known as ammonium. this ion is created when the gas form NH3 dissolves in water H2O. NH3 + H2O = NH4+ + OH-
it's less harmfull and depends on PH if u get more ammonia NH3 or ammonium other than that i'm not positive. the reason ammonium hydroxide is NH4OH is because NH4 and OH are both ions and are kinda stuck together in their own ionic group ...haha my chem teacher would be insulted at my explanation.......sorry thought i'd give it a try tho!!!!!!! )

 

[Alien Anna]

NH4+ is ammonia (a gas, NH3) dissolved in water.

 

[Lateral Line]

Along the right lines but not quite. NH3 is ammonia, a gas which can dissolve in water. The Nitrogen atom in the centre of the NH3 group has a "lone pair" of elctrons, which give the molecule an electrical dipole, it is neutral, but the positive parts are at one end and the negative at the other.

Water is H2O. It can, and does freely dissociate into an H+ ion and an OH- ion, these then recombine.

There are situations when excessive H+ ions can be present, i.e. in acid conditions. When this happens, the negative end of the ammonia molecule "picks up" a positive H+ ion and becomes a slightly more stable, (in water at least), NH4+ ion.

Thus, NH3 will dissolve in water and remain NH3 at high pH, it will hydrate to form NH4+ ammonium ions at lower pH's.

Because the lone pair is covered on an NH4+ ion, it is less biologically active, hence, is regarded as less toxic in the aquarium - the difference is VERY marginal.

Big topic, difficult to explain in simple terms.

 

[Alien Anna]

Thanks Lateral Line - I was trying to keep it simple!

 

[Lateral Line]

>>> Thanks Lateral Line - I was trying to keep it simple!

Believe me so was I

Trouble is, as I said, it's an easy question to ask, but to actually understand the answer, you need to know a whole lot more. I could talk for an hour simply on the physics of a "lone pair"!!!

 

[Alien Anna]

>>> Thanks Lateral Line - I was trying to keep it simple!

Believe me so was I

Trouble is, as I said, it's an easy question to ask, but to actually understand the answer, you need to know a whole lot more. I could talk for an hour simply on the physics of a "lone pair"!!!

I studied biochemistry at university so I'd probably follow what you were on about. However, it might cause a sudden bout of narcolepsy

 

[mrV]

They are not spots of flys s*it, those "spots" describe electrons... + and - describes charge of ions. Although, it's quite simply version, but we don't want to do it too difficult to understant, right? N has 5 electron on its outer shell/orbit (actually there are no shells, electrons move in free space around atom), H has 1 and O has 6. Every atoms want to get octet (8 electrons on outer shell).

As you can see from the image, N has (in NH3 molecule) lone pair as it said on above (lateral-line wrote it). So NH3 can bond atom or molecule. Because O has greater electronegativity (in H2O molecule) it pulls those electrons and H looses its only electron to O -atom (when NH3 is present).

If only it helps...

 

[Lithril]

Yup I studied Chemistry at uni and still feel the urge to start snoring

 

[Feline]

Very interesting! Didn't realise there's so much behind this! Thanks guys!!

 

[canis_lupus]

haha my explanation was a little vague eh? well what can u say for grade 12 chem!