What is the solvent of gold?

Question

1159 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-02-20T16:50:44

Well, if you want to know a system that can dissolve gold, we can point to so-called #"aqua regia"#...

And #"aqua regia"# is a highly oxidizing species that is formed by mixing conc. nitric, and conc. hydrochloric in roughly equal amounts...

The nitrogen in nitrate is reduced to #N(IV)# in #NO_2(g)#

#NO_3^(-) +2H^+ +e^(-) rarr NO_2(g)+H_2O(l)# #(i)#

And gold is oxidized to #Au^(3+)#

#Au(s) rarr Au^(3+)+3e^(-)# #(ii)#

And so we add #3xx(i)+(ii)#....

#Au(s)+ 3NO_3^(-) +6H^+ +3e^(-) rarr Au^(3+)+3e^(-)+3NO_2(g)+3H_2O(l)#...

#Au(s)+ 3NO_3^(-) +6H^+ rarr Au^(3+)+3NO_2(g)+3H_2O(l)#...

And we could adapt this by adding #4xxCl^-# to each side....

.#Au(s)+ 3HNO_3(aq) +4HCl(aq) rarr HAuCl_4(aq)+3NO_2(g)+3H_2O(l)#...