Question #f5981

1 Answer
May 23, 2017

The oxidation number of #Mn# in #MnCl_2# is +2 while its oxidation number in #MnO_2# is +4.

Explanation:

With a few exceptions, the oxidation number of an element is equal to its charge. In #MnCl_2#, the charge/oxidation number of the #Cl# atom is -1 since it is in the halogen family, and since the molecule #MnCl_2# has 2 #Cl# atoms, it has a -2 oxidation number. Assuming your compound is a neutral compound with no overall charge, #Mn# would have a +2 oxidation number in the compound.

For #MnO_2#, #O# has a -2 charge/oxidation number, so 2 #O# atoms would have a charge of -4. This means #Mn# has an oxidation number of +4 in order to make the neutral compound.