Chemistryhard · Past Paper

What is the oxidation number of Cr in $K_2Cr_2O_7$?

A+3
B+6
C+7
D+12

✓ Correct Answer: B+6

2(+1) + 2(Cr) + 7(-2) = 0 => 2 + 2Cr - 14 = 0 => 2Cr = 12 => Cr = +6.

Share this question

More from Chemistry