Preparation of ferrous ammonium sulphate

[pyroglycerine]

Hi,

 

Today in my Inorganic Chemistry Experiments class we conducted the experiment: 'Preparation and analysis of the composition of ferrous ammonium sulphate'.

At the end of the experiment we dissolved 1g of our ferrous ammonium sulfate crystals in pure water and then added 1mL of 6mol/L HCl and 1mL of 1mol/L KSCN solution. Extra pure water was added to bring the solution in the test tube up to 25mL. We then made a semi-quantitative colourimetric measurement to determine if it was I, II, or III 'colour reagent level'(is that correct? maybe I translated it wrong).

 

My question is: Is the 'colour reagent level' the same thing that is indicated in, for example, ammonium Iron(II) sulphate ? If so, why when I search the internet does 'ammonium Iron(I) sulphate not exist? I can only find ammonium iron(II) sulphate and ammonium iron(III) sulphate.

 

I'm studying my BSc in Chemistry here in China and it's all in Chinese (my native language is English), so sometimes it's hard for me to ask questions or understand some things, hence why I'm asking you here.

 

Thanks in advance for all your help.

 

Pyroglycerine

 

 

[pyroglycerine]

Disregard the above, answered it myself.

However, I am still puzzled as to why I can not find any information on Ammonium Iron(I) Sulphate on the internet. Does it not exist, or have a different name?

[John Cuthber]

Ammonium iron (I) sulphate wouldn't exist.

In general Fe(I) compounds are a bit of an oddity. As far as high school chemistry is concerned, they don't exist.

[pyroglycerine]

Ammonium iron (I) sulphate wouldn't exist.

In general Fe(I) compounds are a bit of an oddity. As far as high school chemistry is concerned, they don't exist.

 

Thanks ..I've been waiting for an answer for this for a while ..

 

So,why would they not exist,could you explain please?

So I'm assuming that that they were just using I, II and III as an indication of colour and not oxidation state then?

It's university, not high school.

Edited April 12, 2014 by pyroglycerine