Which of the following is not an antioxidant?

Butylated hydroxybenzene

The correct answer is Option (4) → Butylated hydroxybenzene.

Let us look at substances mentioned in the options:

1. Butylated Hydroxytoluene (BHT):

BHT is a well-known antioxidant. It is widely used in the food and cosmetic industries to prevent the oxidation of fats and oils, which helps to preserve products and extend shelf life.

2. Sulphur Dioxide \((SO_2)\):

\(SO_2\) acts as an antioxidant and antimicrobial agent. It is used as a preservative in the food industry, especially in wines and dried fruits, to prevent oxidation and microbial growth.

3. Sulphite \((SO_3^{2-})\):

Sulphites are salts or esters of sulphurous acid, and they act as antioxidants. They help in preventing oxidation in foods and beverages, especially in products like dried fruits and wines.

4. Butylated Hydroxybenzene:

The term "butylated hydroxybenzene" is not widely recognized as a distinct chemical name. However, it might be a mistaken or vague reference to BHA (Butylated Hydroxyanisole), which is an antioxidant.

Since the question lists "Butylated hydroxybenzene" separately from BHT and does not explicitly mention BHA, this suggests it is either a misinterpretation or simply doesn't refer to a known antioxidant in the given context

Why the correct answer is Option 4 (Butylated Hydroxybenzene):

In this case, the substance "Butylated hydroxybenzene" is not recognized as a common antioxidant. Given that the other substances (BHT, SO₂, and sulphites) are all known for their antioxidant properties, Option 4 would be the most appropriate choice because it doesn't represent a standard antioxidant.

Thus, Option 4: Butylated hydroxybenzene is correct because it doesn't match a known antioxidant, unlike the others in the list