Water

Unique Features High surface tension Low vapor pressure High specific heat capacity High boiling point All are the result of hydrogen bonding.

Surface Tension The inward pull that minimizes the surface area of a liquid Water forms Hydrogen bonds so it has high surface tension Surfactants decrease surface tension by interfering with the Hydrogen bonds Soaps or detergents

Solvents and Solutes Solvents and solutes together make up a solution Solvation (dissolution) – the process of making a solution

Electrolytes Electrolytes are compounds that conduct an electric current in aqueous solution or their molten state All ionic compounds are electrolytes Most molecular compounds are nonelectrolytes

Strong vs. Weak Strong- almost all the solute exists as separate ions. (KCl) Weak – only a small fraction of the solute exists as ions (NH3)

Water of Hydration Some compounds contain water as part of their formula unit (CuSO4 5H2O) When heated above 100 degrees Celsius, the water is lost and the crystals crumble If water is added, the crystal is reformed

Hygroscopic Salts and other compounds that remove moisture from the air to form higher hydrates CaCl2 H2O  CaCl2 2H2O Used as drying agents (desiccants) Deliquescent compounds remove so much water that they are able to form solutions

Suspensions Heterogeneous mixture Particles settle out upon standing Particles in a suspension are larger than those in solutions (100nm or larger) Muddy water

Colloids Heterogeneous mixture Particles in colloids are smaller than those in suspensions but larger than solutions Particles = Dispersed phase Found in the Dispersion medium Foams, emulsions, aerosols, smoke, gels

Tyndall Effect Scattering of light