Question

Redox Reaction Help?

• Write and balance the following molecular equation. Remember to show oxidation numbers for each element on the reactant and product side of the equation. Identify what species is oxidized and what species is reduced, and write their half-reactions.

Au(s) + HNO3 (aq) = ?

Thanks!

Answer 1

I don't believe a reaction will take place. (Please see comments for follow-up questions and original answer!)

Explanation:

For the follow-up questions:

`Fe + Pb(NO_3)_2`: This reaction will take place. It is a single-displacement reaction again, and iron places higher than lead in an activity series. This means that iron will displace lead.
The balanced equation is: `2Fe + Pb(NO_3)_2 -> 2FeNO_3 + Pb`

`Ag + NiCl_2`: Silver is lower than nickel on an activity series, so that means it's not going to displace nickel to form `AgCl`.

`Cl_2 + KI`: This reaction is unique because, instead of a metal possibly displacing another metal, this is a nonmetal possibly displacing another nonmetal.

To figure out if this reaction will take place, just take a look at an activity series for nonmetals—when you do, you'll find that `Cl` is at the top, and `I` is at the bottom. This means that chlorine will displace iodide.
The balanced equation: `Cl_2 + 2KI ->2KCl + I_2`
Iodine is `I_2` because it's a diatomic.

Answer 2

Typically we would expect aqua regia to oxidize gold; a 1:1 or 3:1 mix of conc, hydrochloric and conc. nitric acids....

Explanation:

See this old answer....