Nitric acid question

[peter i]

Dissolve silver nitrate in distilled water, a 0.5 molar solution is what I use, in an eye dropper bottle.

Place a drop of the solution you want to test on a black glaced tile or similar* (a piece of glass on a piece of black paper will do the job too), then add a drop of the silver nitrate solution to it.

A white precipitate (drop becomes milky) is positive test for chloride (precipitate is silver chloride).

Edit:
iodide and bromide will give a yellow precipitate and Sulphate will also precipitate white with silver in higher concentrations.
Silver halides will dissolve if you add a drop of ammonia, silver sulphate will not.

*IKEA sell a nice black dinner plate that is great for this test 8)
http://www.ikea.com/webapp/wcs/stores/servlet/IkeamsSearch?storeId=14&langId=-12&catalogId=11001&searchType=product&pageNumber=-1&orderBy=score&category=%23%7EProducts&query=sort+tallerken

 

[Anonymous]

I believe I read how to concentrate the sulfuric from battery acid in the tutorials. Look through them carefully the information is there because I learned it from this forum.

I will try and duplicate my initial searches to see if I come up with the right thread.

 

[lazersteve]

Here's the link:

Sulfuric Acid

Catfish won a forum contest with this tutorial.


Steve

 

[Oz]

I am just beginning in chemistry so if you could please indulge me, I would not know how to make a 0.5 molar solution. I do have the ability to weigh to a 10th of a gram accurately, as to volume sad to say I need burettes (sp.) as I am using a kitchen measure cup in ml currently.

As to iodide and bromide, it is nice to know the color indicators for this solution but are you suggesting I may have difficulty seeing the color difference?

From what you are saying if I get a mixed precipitate I can re-dissolve the iodide and bromide (halides?) with ammonia (household concentrations?). If I then washed the remaining precipitate with distilled water I should only be left with silver chloride or silver sulfate? Suggestions as to how to tell if I have a silver chloride or silver sulfate left?

Peter, Thanks for the tip on a black background!

Steve, Thanks for the link! It’s even more detailed than what I had found elsewhere.

 

[lazersteve]

Oz,

One mole of silver nitrate weighs 169.88 grams. So 0.5 moles is :

169.88 * 0.5 = 89.94 g

In chemical terms the upper case M stands for Molarity or Moles Per Liter.

So a 0.5 M solution of silver nitrate is 89.94 g of AgNO3 with water added to the 1 Liter mark (approximately 1000 mL - 19.6 mL = 980.4 mL). The 19.6 comes from the specific gravity (4.35 g/mL) of AgNO3 (89.94g / 4.35 g/mL =~ 19.6 mL)

Steve

 

[peter i]

I am just beginning in chemistry so if you could please indulge me, I would not know how to make a 0.5 molar solution. I do have the ability to weigh to a 10th of a gram accurately, as to volume sad to say I need burettes (sp.) as I am using a kitchen measure cup in ml currently.

Steve gave the recipe, and I'm sorry that I did not. When it's daily routine I tend to forget that molar concentrations are not the usual measure.

No need to be exact, you are only testing qualitatively to see if it is there or not (another lab-habit: .5 M can be anything from 0.45 to 0.54M. 0.500 is on the other hand an exact concentration, or rather from 0.495 to 0.504 M)

As to iodide and bromide, it is nice to know the color indicators for this solution but are you suggesting I may have difficulty seeing the color difference?

Yes, especially if it is in a green/blue/yellow solution or of unknown concentration.
But a positive test show that they are there (one or more of them, most likely chloride)

From what you are saying if I get a mixed precipitate I can re-dissolve the iodide and bromide (halides?) with ammonia (household concentrations?). If I then washed the remaining precipitate with distilled water I should only be left with silver chloride or silver sulfate? Suggestions as to how to tell if I have a silver chloride or silver sulfate left?

silver chloride, -iodide, and bromide are all silver halides, and will dissolve in ammonia.
Silver sulphate will not.
This allows you to see if it is sulphate or halogen that cause the precipitation.

Peter, Thanks for the tip on a black background!

My pleasure


And another tip:

When cementing silver with copper, test the solution for remaining silver in exactly the same way, but use a dilute hydrochloric acid as reactant. Any remaining trace of silver in the solution will give the same reaction (the silver chloride don't care where silver or chloride comes from. If both are present, they will precipitate)

 

[Oz]

By all means please don’t stop with the finer points. I don’t mind at all if you continue using moles, but please include the molar weight of the compound as well. I’m not just here for a recipe I love seeing the details. I’ll have to play around with some of this using the periodic table of elements as I wait for my silver nitrate to arrive. As money is tight right now for reference book buying does anyone know a good online source where I could find solubility charts for the different salts at varying temperatures. I had in mind trying to purify my sodium nitrate along the lines that Steve is using in his poor mans nitric acid recipe to remove the excess sodium and sulfide.

Thanks again

 

[goldsilverpro]

Some old downloadable Google books of Solubilities

http://books.google.com/books?hl=en&id=d1JMAAAAMAAJ&dq=solubilities&printsec=frontcover&source=web&ots=BSNxePB4lB&sig=Sy90gRGtSQshDPiIno_3Hx_urLQ

http://books.google.com/books?id=7L0MAAAAYAAJ&printsec=frontcover&dq=solubilities+inorganic&lr=

 

[peter i]

The molar mass can also be found on wikipedia for any common chemical (and the basic characteristics of the chemical. Use wiki-data with caution, but normally it's quite good)

 

[Oz]

Ok, I got my .995 silver nitrate today so went at the fertilizer. To keep it as precise as possible (with what I have at hand) I mixed up a solution of 1 cup distilled water and 2 tablespoons of Bonide brand 15-00-00 nitrate of soda and stirred until dissolved. I also made up a 0.5M solution of silver nitrate and distilled water using Steve and Peter’s directions. In a black plastic melon ball scoop I placed 5ml of the nitrate of soda solution and added to it 1.25ml of my silver nitrate solution. In order of reactions....

Bottom Pic: After adding silver nitrate, As you can see it curdled immediately.

2nd pic: After I added 5ml of household ammonia. It cleared in a blink of the eye.

Top pic: Here it is after 2 washes in ammonia (setting in 2nd wash)

Since I did not dry and weigh between steps I can only guess but it was pretty close to a 50% reduction of solids after the addition of ammonia. I did not notice any other colors through the process Peter. So it would seem in that I did indeed have 50% of my precipitate as a chloride.

So I guess that leaves me with trying to separate the nitrate from this solution (perhaps in freezer) or distilling as Peter had originally suggested. Would the chloride cause a problem if I used distillation?

I hope this comes out OK as it is the first time I have tried to attach pics.

Thanks,
Dave

 

[Oz]

Sorry about the goofy order, I should get it right next time. At least I found edit. By the way how worried do I need to be about this quote I found “Silver Nitrate is soluble in Ammonia (Forms explosive di-amine silver upon drying!)”

 

[calgoldrecyclers]

Dave,
are you thinking of silver nitride? or ammonical silver nitrate?
silver nitride will form over a period of two to three hours.
however, for the formation of silver nitride, you are missing a key ingredient.
on a safety note: ammonia should never be added to oxidizers.

 

[Oz]

It was a caution I had read from a supplier when I was looking for the cheapest price on high purity silver nitrate. There are several procedures that are being done by members here that use ammonia as a wash to remove traces of silver salts from precipitated gold. What I just did for testing nitrate vs. chloride could have in theory made di-amine silver nitrate if I understand correctly. I do have everything in very small amounts and the nitrate portions very diluted with water and disposed of just to be sure.
I used to have a bit of fun with ammonia and crystalline iodine soaking paper in this and letting dry. The warning I saw on the silver nitrate reminded me of this considering all the filtering that is done by members, leaving the filters to dry for later recovery by incineration. The ammonia iodine is something that you do not want to filter through paper and let dry and I would not even trust it in solution in a glass stoppered jar due to the possibility of crystallization near the lid, sensitivity is extreme.
I am not a chemist but do know more than your average citizen about explosives as I had a research physicist as a father that specialized in inventing new explosives for our military. A lot of what is done with chemical refining of precious metals walks down a fine line with explosives manufacture and I want to keep everyone safe. I am hoping that someone here that is a chemist can provide some answers on this as I am not familiar with this compound.
I am comfortable with heavy dilution but want to know if it is needed or if those that may be filtering this and letting dry may have a potential problem.

 

[calgoldrecyclers]

Dave,
i couldnt agree with your statement ' alot of what is done with chemical refining of precious metals walks down a fine line with explosives manufacture' more. it is a very slippery slope. nitric acid being one of the more dangerous of the acids.
i read somewhere, a report of silver nitrate being mixed down with ammonia under heated conditions without reaction.
i will see if i can locate it and let you know.
in the mean time, you may want to check out this site:
www.chem.leeds.ac.uk/ or www.lycoming.edu

good luck,
Ezra

 

[Lou]

Oz, Peter and I have written a thread about ammoniacal silver solutions.
Search up "Tollen's" by Lou and you should find it.

I have a couple pounds of ACS grade AgNO3 if you want it Oz. I only want 98% of the spot value of the silver metal in it.