what's the meaning of reagent grade (17M) of ammonium hydroxide ?And how does make it

[qinfp]

 

 

what's the meaning of reagent grade (17M) of ammonium hydroxide ?And how does make it? ammonium hydroxide=ammonia water？

thank you very much!

[YT2095]

Reagent grade is a standard Lab grade for general work, it gives an indication of it`s Purity.

the 17M tells you how Strong/Concentrated the soln is.

 

Ammonium hydroxide is NH4OH, and made by bubbling NH3 in H2O.

 

I`ve never heard of "Ammonia water"?

[John Cuthber]

Ammonium hydroxide is a myth; it might exist under some weird low temp/ high pressure conditions.

Ammonia dissolves in water; the product is known by various names. Aqueous ammonia and ammonia water are 2 of the common ones.

 

If I try to make ammonium hydroxide by, for example reacting sodium hydroxide with ammonium chloride in solution nothing much should happen. I should get a solution containing ammonium ions sodium ions chloride ions and hydroxide ions. (certainly, if I do this with potassium chloride and sodium hydroxide in solution nothing happens unless the concentrations are so high that salt doesn't dissolve in water)

In the real world the mixture gets warm and gives off ammonia. This is because the ammonium ion is a relatively strong acid and the hydroxide ion is a strong base; they cannot co exist (certainly not at any meaningful concentration) because they react with eachother. The proton hops across from the NH4+ to the OH- and gives ammonia and water.

 

The misleading nomenclature persists, partly for historical reasons (ie "we always called it that") and mainly because it sounds better to say 14% ammonium hydroxide than (roughly) 7 % ammonia. See, it's a bigger number so it sells better.

If ammonium hydroxide existed it would have a molecular weight of 35.

A 14 M solution would have 14*35 ie 490g of "ammonium hydroxide" but would really just have 14*17 ie 238 g of ammonia per litre.

It's the same stuff but it looks like it's 49% (w/v) rather than 23.8%(w/v).

Find me some data on the N O distance in NH4OH and I will think about believing in it; otherwise, since this is a scientific site, lets try to stamp it out.

[qinfp]

thank you very much again!

[kizm0]

So to make "14% Ammonium Hydroxide and Distilled Water solution" all I would do is have 86% water, and 14% ammonia?

[John Cuthber]

No you would need roughly 7% ammonia to get what might be called the equivalent of 14% ammonium hydroxide.

Incidentally pure NH3 is a very soluble gas. I doubt that, if you need to ask this sort of question, you will be able to get pure ammonia.

 

BTW, you are not meant to cross post so please delete your other post about this.

[iNow]

How does a user without staff level system permissions delete their own post?

[John Cuthber]

Oops.

They ask someone to do it for them.