What is the oxidation number of chromium in K2CrO4?

A. +1
B. +2
C. +4
D. +6

Correct Answer: Option D

D. +6

Explanation

K2CrO4 (O.N of K) X 2 + O.N of Cr + (O.N of oxygen) X 4 = 0
1 X 2 + X + -2 X 4 = 0
2 + x + -8 = 0
2 + x – 8 = 0
x = 8 – 2 = + 6