Question

Write balanced equations of (1) Acidified Potassium Dichromate with H2S (2) Potassium permangnate with KI in alkaline medium​

Answer 1

K2Cr2O7+7H2SO4+6KI→4K2SO4+Cr2(SO4)3+7H2O+3I2

We have Cr2(SO4)3  in the product in which the oxidation state of Cr is calculated as:

Let, x is the oxidation state of Cr, so, 

2x +3(-2) =0

x=+3