What is the product when K 2 Cr 2 O 7 reacts with H 2 S in acidic medium?
Cr 2 O 7 2– oxidizes H 2 S to S (yellow precipitate) and reduces to Cr 3+ (green).
Ref: NCERT Class 12 Chemistry > Chapter 4: d and f Block Elements > Topic: Oxidation States and Colour and Magnetic Properties of d-Block