Solutions and Solvents

Chemical Reactions in Solutions

• Chemical reactions in the human body occur in solutions.
• A solution is a homogeneous mixture of two or more substances.

Terminology of Solutions

• Solute: Substance that dissolves.
• Solvent: Substance in which the solute dissolves.
• Example: Instant tea in water
  • Water is the solvent.
  • Tea is the solute.
  • The tea dissolves into the water, creating a homogeneous solution.

Concentration of a Solution

• Refers to the amount of solute present.
• Example: 10% salt solution
  • 10% of the molecules are salt (solute).
  • 90% of the molecules are water (solvent).

Water as a Solvent

• Water is often referred to as the universal solvent.
• Body fluids (blood plasma, cerebrospinal fluid, tears, saliva, cytoplasm) are water-based solutions with dissolved solutes (salts, nutrients, gases).
• Sense of smell and taste rely on substances dissolving.