CHEM 110 Lecture Notes - Lecture 10: Ultimate Tensile Strength, Lone Pair, Surface Tension

• School: McGill University
• Department: Chemistry
• Course: CHEM 110
• Professor: Christopher Barrett

Document Summary

Chem 110 lecture 10 the unique properties of water. Lecture date/time: sept 30th, 2015 / 10:35-11:25 am. Polar forces in asymmetric molecules are the essence of most liquids. In a liquid state they ^ orient to the lowest energy state & they have enough free motion available that they maximize attractions. Water"s density is unique compared to all other molecules: Normal trend for other molecules is that the more dense = the colder it is. But water instead peaks in density a bit above the freezing point, & becomes less dense when it freezes/solidifies (unlike anything else) This is the reasoning behind so many biological and biochemical functions: Ice expansion in crevices in mountains, etc, breaks up the rocks & eventually forms soil. Side note: just think that ice cubes in drinks float! Tetra-valent structure but only bonded covalently twice = 2 lone electron pairs on oxygen are free to h-bond to the other hydrogen atoms of other water molecules.