why is iodine dissolved in alcohol and used as tincture of iodine on wounds?
2 answers
Because it kills bacteria.
Iodine is not very soluble in water. It is more soluble (somewhat) in alcohol AND tincture of iodine has KI dissolved in it which makes I2 VERY soluble. As Bob Pursley has pointed out, the alcohol and the iodine are good at routing bacteria.