Final answer:
A solution created by dissolving a solid or gaseous antimicrobial chemical in pure alcohol or an alcohol-water mixture is known as a tincture.
Step-by-step explanation:
Dissolving a solid or gaseous antimicrobial chemical in pure alcohol or an alcohol-water mixture produces a tincture. Alcohols such as ethyl alcohol (ethanol) and isopropyl alcohol (isopropanol, rubbing alcohol) are commonly used as disinfectants and antiseptics. They work effectively by denaturing proteins and disrupting cell membranes. In the case of ethyl alcohol, a 70% aqueous solution is more effective than a 100% alcohol solution for inhibiting microbial growth because the presence of water allows the alcohol to penetrate cells more effectively and prevents the rapid coagulation of surface proteins.