A colored gas, containing chromium

[woelen]

I want to share with you a nice experiment with a colored gas, which contains chromium. It looks like bromine, but in reality it is a very volatile metal-compound!

 

http://81.207.88.128/science/chem/exps/volatile_chromium/index.html

 

Have fun. If you repeat the experiment, please be very careful. The gas is really toxic!

[Mendelejev]

Mmm, very nice experiment. I'm certainly going to try it ! I'll let you know if it worked well or not. But I was wondering. Aren't there nice experiments with chromyl chloride for example ?? Would be nice

[woelen]

Mmm, very nice experiment. I'm certainly going to try it ! I'll let you know if it worked well or not. But I was wondering. Aren't there nice experiments with chromyl chloride for example ?? Would be nice

Yes, you can do nice things with chromyl chloride. You can dissolve this stuff in relatively inert organic solvents, such as ligroin (Dutch: 'laagkokende wasbenzine' / 'petroleumether'). The solution in ligroin then can be used for other experiments, such as oxidation of organic compounds in non-aqueous solvents. The stuff, however, should not be stored, as it is quite unstable and with some organics, it forms explosive mixtures or may cause fire. It also eats almost everything. It is even worse than bromine on storage. I kept it in the little bottle for just a few hours and in that short time, the plastic screw-cap already was severely corroded.

 

You can make a solution in ligroin, simply by adding some ligroin to the mixture. With a glass pipette, you can carefully take away the ligroin layer, with some of the CrO2Cl2 dissolved in it. The ligroin remains above the sulphuric acid layer.

[akcapr]

wow u are smart, how do u come up with experiments like this? (great way to continue my inorganic exp.'s)

[budullewraagh]

really toxic and carcinogenic.

 

good idea though; sounds like an interesting compound. i'm half tempted to make some, but the gas is so dense and such a strong oxidizing agent that any inhalation would probably prove fatal

[woelen]

really toxic and carcinogenic.

 

good idea though; sounds like an interesting compound. i'm half tempted to make some' date=' but the gas is so dense and such a strong oxidizing agent that any inhalation would probably prove fatal[/quote']

Well, it is toxic (carcinogenic), but a small whiff of this gas won't kill you. Of course you should do your best to not inhale any of this gas, but if you do inhale something, then it is not fatal. In fact, I accidently could smell some of the gas after taking the picture with the gas in front of the bottle in the air and I left the place immediately, but I'm still here to show you the results. Remember, I only used approximately 100 mg of K2Cr2O7, so the whiff I inhaled probably will be in the microgram range. The smell actually is quite strange: sweet and spicy.

[woelen]

wow u are smart, how do u come up with experiments like this? (great way to continue my inorganic exp.'s)

Buy a good old book on chemistry. Pre-war books are best. These books describe all kinds of compounds, which can be made with fairly common chemicals. Especially books in the German language are very nice. Apparently before WW II, the German chemists were focussing more on compounds and processes.

I have books with 1000+ pages from 1920 and 1915 and these describe all kinds of compounds. With these books at hand and a little reasoning you can come up with many cool experiments.

 

Modern books focus much more on theory, which on its own is OK, but sometimes they tend to go too far with this. Just knowing the basic properties of common compounds makes chemistry much more fun.

[Mendelejev]

Correct. I have some old books of "chemistry", almost "kitchen chemistry", in fact a mix of alchemy an chemistry and cooking. But extremely interesting !! The first chapter is "Het vervalschen van goud' ! Means : 'adulterating (?) gold' with some common metals.

 

I search in old bookstores, but it's hard to find old books on chemistry. Maybe if I go to Germany, I could find something interesting. Becouse, yes it's true, during WWII, the germans were very good in chemistry (think of Haber for example), and they have written some great books.

 

Also the book of Oliver Sacks 'Uncle tungsten' is a nice book. Not really descriptions of the experiments, but it could give you some new ideas. Schoolbooks for the basic experiments. History books, for old experiments, like Hennig Brand's extraction of P