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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: kuromi on April 11, 2009, 12:38:53 PM

Title: [Fe(NCS)]2+ qutestion !!
Post by: kuromi on April 11, 2009, 12:38:53 PM
Fe3+(yellow)   +   NCS- (colourless)     <->   FeNCS2+  (blood red)

 when i add one more drop of Fe3+ solution into test tube
and one more drop of NCS-solution into other test tube

explain why  added Fe3+ solution is blood red while added  NCS-solution is reddish dark ? 

By le Chatelier's principle , the equilibrium position shifts from left to right when conc . increased .  why  the colors are different ?
 
Title: Re: [Fe(NCS)]2+ qutestion !!
Post by: BluRay on April 11, 2009, 03:49:25 PM
Fe(SCN)2+ is not the only compound formed. There are also Fe(SCN)2+ and Fe(SCN)3 and they probably are of different colours.
Title: Re: [Fe(NCS)]2+ qutestion !!
Post by: Astrokel on April 11, 2009, 04:05:43 PM
Think about what happened to the other reactant and the end result of the combination of colour when you adding Fe3+ or thiocyanate.
Title: Re: [Fe(NCS)]2+ qutestion !!
Post by: kuromi on April 12, 2009, 12:44:49 AM
thank you for your ans.

 ;) ;)