Question

oxidation question

Answer 1

what is the oxidation number of Cr....

so what i reasoned was that since O has a -2 (except in peroxides) and multipling it by 7 will give you -14

and what i know for Cr is that it mus be +12
BUT
the oxidation # for Cr is the ionic charge "+3" since Cr is monatomic so 3 multipying two is +6 so how do i get twelve?

Answer 2

@hoslos

Answer 3

ok nvm i think i get it

Answer 4

what is the question ?u want the oxidation no of cr

Answer 5

correct, i think the problem was that i thought Cr oxidation number has to be the ionic charge +3 becuase its monatomic but its not a set number, it could be used in some case or not and in this case your trying to have a net charge of -2 becuase its a polyatomic ion therefore +6 ..... not +3