vmelkon - 7-1-2015 at 20:13
I did electrolysis of conc NaCl solution for 24 hours. I added some 6 M H2SO4. I did this in a 1000 mL flask and it smelled like chlorine. The gas
inside the flask is green.
Is this chlorine?
The temp during the electrolysis was probably above 50 °C.
I imagine some NaClO and NaClO3 formed. Perhaps the chlorine comes from 2 NaClO + H2SO4 → Na2SO4 + Cl2 + H2O
What about the NaClO3?
Hawkguy - 7-1-2015 at 21:13
Maybe like Chlorine Dioxide, or Chloric Anhydride or whatever... Could be many things, also depending on the quality of your reagents...
vmelkon - 7-1-2015 at 21:39
I was worried about Chlorine Dioxide.
Fulmen - 8-1-2015 at 02:25
I think both chlorine and chlorine dioxide are possible products from the breakdown of chloric acid. Hypochlorous acid should produce chlorine gas.
I think it's hard to use color here, both Cl2 and ClO2 are yellow/green while Cl2O is brownish-yellow.
woelen - 8-1-2015 at 04:11
The gas mix above the liquid is mainly colored by ClO2 and a little bit by chlorine. The color of ClO2 differs a lot from the color of Cl2. ClO2 has a
very intense color and even dilute gas can be observed easily. Cl2 only has a weak color and only the pure gas in sufficient thick layers can be seen.
Cl2 is green, ClO2 is much more yellowish, a little bit like the color of yellow/green marker pens.
ClO2 can explode, but if its color is only as weak as that of chlorine, then it is very dilute and then you have little to fear.
Cl2O is not present in the gas mix. This gas hardly can exist in the presence of water, it is hydrolysed nearly 100% to HOCl, which remains dissolved
in water. In the presence of chlorate or chloride in acidic solution, HOCl cannot exist.