Lecture Notes - DipolesandWater ,theweakelectrical otherp

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Dipoles and Water Water molecules are highly polar because O is  more strongly attractive for electrons than H. When a slightly positive H atom comes close to  a slightly negative O atom, the weak electrical  attraction results in a hydrogen bond. Due to the high polarity of water molecules,  other polar molecules or molecules that carry  plus or minus charges readily dissolve in water. Such molecules are referred to as hydrophilic. Molecules that are uncharged and form few or  no hydrogen bonds do not dissolve in water and  are termed hydrophobic.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
When a hydrogen bond forms between two water molecules, the  redistribution of electrons changes the ability for further hydrogen  bonding.  The water molecule donating the hydrogen atom has increased  electron density in its 'lone pair' region, which encourages hydrogen  bond acceptance The accepting water molecule has reduced electron density  centered on its hydrogen atoms and its remaining 'lone pair' region,  which encourages further donation but discourages further  acceptance of hydrogen bonds This electron redistribution thus results in increased hydrogen bond  formation among water molecules Cooperative hydrogen bonding  increases the O-H bond length  while causing a 20-fold greater reduction in the H∙∙∙∙O and O∙∙∙∙O 
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/22/2010 for the course BE 2400 taught by Professor Goldman during the Fall '08 term at Michigan Technological University.

Page1 / 17

Lecture Notes - DipolesandWater ,theweakelectrical otherp

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online