BSC 197 Lecture Notes - Lecture 3: Polystyrene, Covalent Bond, Surface Tension
29 Dec 2016
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Document Summary
Structure of water: one large oxygen atom and two smaller hydrogen atoms, covalently bound, polar molecule (oxygen- negative, hydrogen- positive) not fully charged. Hydrogen bonding: occurs between hydrogen of one water molecule with oxygen of another, one molecule may make hydrogen bonds to 4 other molecules, weak and transient bonding (1/20th as strong as a covalent bond) Cohesion/adhesion: cohesion: water molecules bond together. Allows surface tension: adhesion: water molecules bond to other surfaces. Allows water to cling to vertical surfaces (water reacts with carbohydrates to cling be it is polar) Thermodynamics of water: water requires a lot of energy to heat. Buffers temperature of ponds, lakes, oceans and organisms (continental effect- regions farthest from body of water will see dramatic differences of temp in lowest of winters and highest of summers) 1 cal= the energy to raise one gram of water one degree: evaporation of water results in cooling of surfaces.
