rvdzero

hey all, i lost my internet for awhile there thanks to storms. anyways, thanks alot for the links! i did the test for nitrogen and it indeed went prussian blue. so my last question is, hcn has a boiling point of 26 degrees C and benzaldehyde has a boiling point of 178 degrees C, so could one set up a distillation and heat the solution to release hcn gas? (the gas would be bubbled into a cooled, agitated solution of sodium hydroxide to form sodium cyanide. the sodium cyanide would then be added to a hydrogen peroxide solution to form sodium cyanate, which is less toxic. any ideas?

thanks for all the help guys! sorry for lack of posting, have been over seas for the last 3 weeks. anyhoo, im back and just more more question about hcn. how would one attempt to detect if a solution has hcn present? (without all fancy technology lol) a hint in the right direction would be great! ive done a few searches, but i havent found anything yet. just curious about how they detect certain chemicals in solutions. thanks, rick

haha its like the battle of the super powers! you guys really know what your'e talking about! i appreciate being able to learn from both of you, thanks! (one day i hope to be at that level. if you dont mind my asking, what did you guys study / what are your professions? im studying to be a chemical engineer, still got a looong way to go though) so back to the question. all ihave available is silver nitrate. i can react two aqueous solutions of silver nitrate and sodium carbonate, and should be left with a precipitate of silver carbonate (AgCO3 is insoluble in water, well i read 33mg/L) and an aqueous solution of sodium nitrate. 2 AgNO3 (aq) + Na2CO3 (aq) => Ag2CO3 (s) + 2 NaNO3 (aq) Then, based on YT's answer, if i add the Ag2CO3 to the benzaldehyde and HCN, it should precipitate silver cyanide. Would the carbonate ion claim the hydrogen from the HCN to form HCO3-? if there was an excess of carbonate ions, would they try to break the benzaldehyde's bonds to form more HCO3-? just having trouble figuring out where the carbonate would go? oh i just had another idea, since CO3- would try and take hydrogen from water, couldnt i add a bit of water to the benza/hcn mix? because AgCN is insoluble in water, and so is benzaldehyde. the water would give the CO3 anion somewhere to go/something to react with? thanks, rick

well, if i use silver nitrate as the silver salt, i could use a more reactive metal (aluminium) to precipitate elemental silver. so, 3 AgNO3 + Al3+ => 3Ag+ + Al(NO3)3 (ive read that oxidation of benzaldehyde yields benzoic acid, im not sure about how auto oxidation plays a part here??) HCN + Ag+ => H+ + AgCN since the formation of AgCN liberates hydrogen gas, would i still need to include the bezaldehyde in the equation?

ah true, cheers! how would i do that? would any silver compound do? or does it have to be a solution of dissolved Ag+ ? would the reaction just go, or would i have to apply heat? (sorry for all the q's, had a look for info but couldnt find much. ill keep looking though)

ah cheers! Thanks for the help guys!

ah true. cheers. so basically id need to find something that will force the hcn into the water layer without any side reactions with benzaldehyde? would use of a different solvent help? (like one that benza is soluble in, but hcn isnt?) or is distillation the only way? thanks for the help!

hey i just had a thought and was wondering if it would be possible to remove HCN from benzaldehyde without distillation. benza is slightly soluble in water (i read 300mg / 100ml) and HCN is completely miscible in water. so could i add some h20 to the benz/hcn mixture to form two layers?

ah thanks. i read it recommended using a sulfoxide. so something like dmso. my next question, dmso is miscible in water so would the a 80% aqueous solution still be suitable, or would the presence of h20 interfere?

hey, i was just reading a patent on alkali metal carbonates. US patent : 4,495,107 . (can get the link if needed) Ok so i was wondering, what are my options for a solvent that could dissolve the urea, but not the alkali carbonate? I read that an inert solvent which doesnt really dissolve the alkali carbonate but dissolves the urea can be used. Any thoughts on toluene or xylene? any other suggestions?

Ah sweet as, thank you very much!

hey all! i made some ferric chloride the other day and it was a nice vibrant greeny yellow colour, but over time it had turned brownish. It is stored in a jar. Would the stuff in the jar still be ferric chloride? Thanks, rick

hey thanks for the advice! Would any carbonate suffice? (ie sodium carbonate, or potassium carbonate?) thanks, rick

hey i was just wondering if it would be possible to replace the sulfur from a thio compound with an oxygen. for example: if i have potassium thiocyanate (KSCN) would it be possible to react it with something to replace the sulfur with an oxygen, leaving me with potassium cyanate (KOCN). Any advice/help would be greatly appreciated! thanks, rick

well the flash point is where the vapor will form an ignitable mixture in the air (needs an ignition source though) and the autoignition temp is the temp that the mixture will ignite and continue to burn without a constant ignition source?