To catalyse the reaction and also to prevent the reaction from hydrolysis.
Step-by-step explanation:
- Sulphuric acid is using in redox reaction because sulphuric acid is providing H+ ions which is necessary for this reaction to occur more quickly, but the sulphate ions from the sulphuric acid barely react during this process. So H2SO4 is adding in this reaction to make it more acidic.
- Sulphuric acid is also a dehydrating agent and also a catalyst in this reaction.
- H2SO4 is helping to prevent the hydrolysis by providing excess H+ ions into the reaction. H2SO4 is stable towards the direction of oxidation.