Forgot to label my chemicals..

[Bluebloomer]

Hi all, I know it's stupid, but I forgot to label some bottles with HCL, HNO3, and H2O2.
Because of a death in the family, I had to drop what ever I was doing and 3 months later I'm not sure anymore what liquid is in what bottle. I was in the process of putting half empty bottles together and labeling them, and I was dilluting the hydrogen peroxide.

Now I have to do some tests to identify and properly label the bottles. Would it work to use a piece of copper to identify HCL and nitric acid ?

But then, I have some bottles with 35, 30 and 3 H2O2. Does anybody have a suggetion on how to determine if the H2O2 is dilluted or not ? I might get some nasty surprises if I use the wrong strenght for certain processes.

 

[g_axelsson]

A piece of shiny copper and measuring the density should be enough.

* Copper in diluted nitric acid - dissolving and giving off brown NOx
* Copper in HCl - getting shiny and bright when the oxide is dissolved but the copper isn't dissolving
* Copper in hydrogen peroxide - oxidizes

Then measure the density of the peroxide.
http://www.h2o2.com/technical-library/physical-chemical-properties/physical-properties/default.aspx?pid=11&name=Density-of-H2O2-Solutions

Göran

 

[anachronism]

Great advice Goran.

If I may add to this. Please find below a link to something that will solve all your problems for the future. This link contains a stunningly simple tool in the bottom left quarter of the page that allows you to print professional and more importantly legally compliant labels for all your jars, bottle, and containers for any chemical you use. It's also free.

So go upgrade your work areas to looking "pro."

http://www.avery.com/avery/en_us/Products/Industrial-Solutions/UltraDuty-GHS-Chemical-Labels/GHS-Software.htm

Enjoy guys.

Jon

 

[Platdigger]

Also if you don't have a way to measure density easy enough, you should at least be able to tell the difference between the lowest and either of the higher solutions of H2O2 by a bit of copper in hcl, and adding your unknown peroxide a drop at a time comparing the reactions.

 

[g_axelsson]

Most people dealing with precious metals have a fine scale, then you only need some way to measure a fixed amount of fluid (a beaker, bottle cap, small glass).
You need to do three measurements, the weight of the empty vessel=W0, with water=Wwater, and an equal volume of the unknown fluid=Wfluid.

The density is (Wfluid - W0)/(Wwater-W0) x Density of water.

If you live in metric land then the density of water is 1 kg/dm3 = 1000 kg /m3 = 1 g/ml = 1 kg/l so the equation becomes

The density is (Wfluid - W0)/(Wwater-W0) g/ml.

Göran

 

[Bluebloomer]

Thank you all very much for all the tips and advice !

As soon as I am back home again I will try and work it out.
I'll let you now how it goes, and the label link sound terrific !

thanks again !

 

[goldsilverpro]

There are many ways to separate them. One way is to first smell them all by wafting them.

Wafting:
(1) Stand back from the top of the container about 2 feet (this is usually far enough away), with your head a little higher than the top of the container.
(2) With your hand (preferably gloved - some fumes will chaff your hand and some can even burn you, especially when hot), waft (wave) the fumes from the top of the container towards your nose.
(3) If you can't smell anything, slowly move your nose forward until you can barely smell it.
(4) Memorize that smell.
(5) Rinse off your glove (or, hand).

Assuming that these are commercial strengths: HCl=30-37%, H2O2=3-30%, HNO3=60-70%

The H2O2 is odorless at 3% and some people say it has a very slight acid odor at 30%. The HCl and HNO3 have a pungent acid smell. These 2 are easy to distinguish from the H2O

The HNO3 is considerably heavier than the HCl. 100ml of 32% HCl weighs about 116g. 100ml of 67% nitric weighs about 140g. The weight of 30% H2O2 is about the same as the HCl.

To summarize, you could first smell them all and then see which acid was the heaviest by weighing 100ml samoles.

Another way would be to smell them and then combine 1 drop of each acid (separately) with 1 drop of silver nitrate in a black or dark plastic spoon. A white cloud will appear in the HCl.

 

[Bluebloomer]

I managed to seperate the nitric and the HCL. Put the correct labels on them and stored them for later use as the EU is now monitoring and prohibiting the sale of nitric acid.

Still leaves 3 bottles with H2O2 and no idea if it is dilluted or not.
I once created a vulcano of foam after adding conc. H2O2 to a solution so I want to be extra carefull this time.

What would be my best bet to guesstimate the peroxide strength ? Would PH give a good indication or should I go by weight ?