What is the oxidation state for the ion Cr2O7^2-?

1 Answer
Oct 29, 2015

Oxygen #-2# and Chromium #+6#

Explanation:

The oxidation state of oxygen is always #-2# except in #H_2O_2# it is #-1# and in #OF_2# it is #+2#.

So the oxidation state of oxygen in #Cr_2O_7^(2-)# is #color(red)(-2)#. Assume that #x# is the oxidation state of #Cr# in #Cr_2O_7^(2-)#, then to find #x#:

#(2xxx)+4xx(-2)=-2=> x-8=-2=>x=+6#

Therefore, the oxidation state of #Cr# in #Cr_2O_7^(2-)# is #color(blue)(+6)#.