Iodine as the solute and alcohol as the solvent.
Explanation
A solution is a homogeneous mixture composed of a solute and a solvent. The substance being dissolved is the solute, and the medium in which it is dissolved is the solvent. In pharmaceutical chemistry, the term "tincture" specifically refers to an extract or solution where alcohol (ethanol) is the solvent.
Detailed Analysis:
- Composition of Tincture of Iodine: It is an antiseptic solution prepared by dissolving 2% to 3% of elemental iodine in a mixture of alcohol and water.
- Identification of Solute and Solvent:
- Iodine: It exists as a solid at room temperature and is the substance being dissolved. Therefore, it is the solute.
- Alcohol: It exists as a liquid and serves as the medium for dissolving the iodine. Therefore, it is the solvent.
Key Takeaway:
A tincture is defined by the use of alcohol as the solvent. Tincture of Iodine is a solution of solid iodine (solute) in liquid alcohol (solvent).