Question #9701f

1 Answer
May 5, 2016

Answer:

#"C"_ ((s)) + 4"HNO"_ (3(aq)) -> 2"H"_ 2"O"_ ((l)) + 4"NO"_ (2(aq)) + "CO"_(2(g)) uarr#

Explanation:

You're dealing with a redox reaction in which carbon reduces hot, concentrated nitric acid to nitrogen dioxide, #"NO"_2#, while being oxidized to carbon dioxide, #"CO"_2#, in the process.

The balanced chemical equation that describes this reaction looks like this

#stackrel(color(blue)(0))("C")_ ((s)) + 4"H"stackrel(color(blue)(+5))("N")"O"_ (3(aq)) -> 2"H"_ 2"O"_ ((l)) + 4stackrel(color(blue)(+4))("N")"O"_ (2(aq)) + stackrel(color(blue)(+4))("C")"O"_(2(g))# #uarr#

Here carbon is being oxidized from a #color(blue)(0)# oxidation state in elemental carbon to a #color(blue)(+4)# oxidation state in carbon dioxide.

Nitrogen, on the other hand, is being reduced from a #color(blue)(+5)# oxidation state in nitric acid to a #color(blue)(+4)# oxidation state in nitrogen dioxide.