Tincture of iodine is an antiseptic for fresh wounds. It is a dilute s

Tincture of iodine is an antiseptic for fresh wounds. It is a dilute solution of elemental iodine, which does not contain

water
acetone
alcohol
potassium iodide
This question was previously asked in
UPSC CDS-2 – 2017
The correct answer is acetone.
Tincture of iodine is traditionally a solution of elemental iodine (Iโ‚‚) and an iodide salt (like potassium iodide, KI) dissolved in alcohol (ethanol) and often with some water. The iodide salt helps to increase the solubility of iodine in the solvent. Acetone is a different solvent (a ketone) and is not a standard component of traditional tincture of iodine. While acetone can be used as a solvent in some antiseptic preparations or for cleaning wounds, it is not typically part of the ‘tincture of iodine’ formulation used as an antiseptic.
The elemental iodine is the primary antiseptic agent in tincture of iodine. The alcohol also has antiseptic properties and helps in the penetration of iodine into tissues. Potassium iodide is added to form triiodide ions (Iโ‚ƒโป), which are more soluble in water and alcohol than diatomic iodine (Iโ‚‚), thus increasing the concentration of dissolved iodine available for antiseptic action.