What is the oxidation state of potassium in potassium chromate?

Ans: Chemical Formula of potassium chromate is K₂Cr₂O₇

Let x be the oxidation number of Chromium (Cr)

Also, we know,

the oxidation state of potassium is +1

The oxidation state of oxygen is – 2 .

According to the rule ;

(+1) × 2 + x + (- 2 ) × 4 = 0

+2 + x – 8 = 0

x – 6 = 0

x = +6

Hence, the oxidation state of chromium in potassium chromate is +6.