In wine making, sulphites are added so that sulphur dioxide is released. The role of SO2 and the change in the oxidation state of sulphur are

antioxidant (reducing agent); sulphur changes from +4 to +6

antioxidant (reducing agent); sulphur changes from +4 to +2

oxidising agent which kills yeast; sulphur changes from +4 to +2

oxidising agent; sulphur changes from +6 to +4

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JEE Advanced levelSingle correct optionDifficulty 3 of 3el140

In wine making, sulphites are added so that sulphur dioxide is released. The role of $SO X_{2}$ and the change in the oxidation state of sulphur are

Aantioxidant (reducing agent); sulphur changes from +4 to +6
Bantioxidant (reducing agent); sulphur changes from +4 to +2
Coxidising agent which kills yeast; sulphur changes from +4 to +2
Doxidising agent; sulphur changes from +6 to +4

Answer: A

Sulphite is oxidised by oxygen:

2 SO X_{3} X^{2 -} + O X_{2} - > 2 SO X_{4} X^{2 -}

(balanced in atoms and charge). Sulphur goes from +4 to +6, so sulphite is a reducing agent and protects the wine from oxidation. The two oxidising options need S to be reduced, which does not occur with oxygen present.

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In wine making, sulphites are added so that sulphur dioxide is released. The role of SOX2​ and the change in the oxidation state of sulphur are

Answer: A

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In wine making, sulphites are added so that sulphur dioxide is released. The role of $SO X_{2}$ and the change in the oxidation state of sulphur are