How to write the name of Hau3+ ion using stock notation. For example HAuCl4 is written as.......(lll) chroride. Fill the blank space?

1 Answer
Sep 28, 2017

Answer:

See explanation

Explanation:

To explain this better I'll use reversible reactions.

You think that:
#"HAuCl"_(4(aq)) rightleftharpoons "HAu"_((aq))^(3+)+4"Cl"_((aq))^(-)#

Instead, it is:
#"HAuCl"_(4(aq)) rightleftharpoons "H"_((aq))^(+)+"AuCl"_(4(aq))^(-)#

#"HAuCl"_(4(aq))# is an acid (chloroauric acid), so the hydrogen ion dissociates from the rest of the molecule. A clearer explanation is brought on with the diagram for the acid structure:
http://www.chemical-reagent.com/products/Chloroauric-acid/

So, there is no #"HAu"_((aq))^(3+)# ion, but there is a #"AuCl"_(4(aq))^(-)# ion, called tetrachloroaurate:
http://www.chemistryrules.me.uk/tandp/optiontransitionelements.htm

By the way, the only compound I know fitting the name of _(III) chloride, is Gold(III) chloride (#"Au"_2"Cl"_6#)