BIOC Chapter 2 - Exam 1 Material Jay Silveira PDF

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Exam 1 Material
Jay Silveira...

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Water Forms H Bonds with Polar Solutes - Has an ability to form hydrogen bonds with polar functional groups such as hydroxyls, amines, and carbonyls Hydrophobic Interactions Non polar solutes do not readily H bond to H2O - Only sparingly soluble - Dissolving of such substances is accompanied by significant reorganization of the water surrounding the solute - Water molecules tend to straddle the nonpolar solute such that two or three tetrahedral directions are tangential to the space occupied by the inert solute - Straddling allows water molecules to retain H-bonding possibilities because no HBA, or HBD is directed toward the cage - Multiple non polar molecules tend to cluster together because their joint solvation cage involves less total surface (H-bonding forces nonpolar molecules to cluster together) - Hydrophobic interactions is maintained by the increase in entropy when the warer coalesce and reorganize Amphiphilic Molecules - Fatty Acids: both strongly polar and strongly non polar - Long nonpolar hydrocarbon tail and strongly polar carboxyl head group - The carboxylate fucntion hydrates readily whereas the tail is intrinsically insoluble - Cluster of amphipathic molecules are termed micelles Influence of Solutes on Water Properties: The presence of dissolved substances disturb the structure of liquid water - Fix nearby water molecules in a more ordered array - Ions, by establishing hydration shells create more local order - Hydrophobic substances, make structures within water - SOLUTES GIVE ORDER TO THE SOLVENT Colligative Properties - Freezing point and boiling point can be influenced. Water can Ionize to Form H+ and OH-

Water ionizes because the larger, strongly electronegative oxygen atom strips the electron from one of its hydrogen atoms

Free Hydrogens immediately hydrate to form H3O+ (hydronium ion)

Strong Electrolytes Dissociate Completely in WAter - Electrolyte: substances capable of generating ions in solution, inc electrical conductivity of solution -...