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Unformatted text preview: Ions in Solution
Chemical Principles of Marine Systems
SIO141/CHEM174 Monday, April 6, 2009
1 First, any questions about the course, etc.? 2 The structure of liquid water 3 Shape of water molecule
2 O H
+ H + polar molecule
4 Shape of water molecule electron distribution (polar molecule)
www.lsbu.ac.uk/water/ images/molecul1.gif 5 Structure of water 6 Structure of ice ice 7 http://jchemed.chem.wisc.edu/ What happens when you add "heavy" ice to normal water?
8 http://jchemed.chem.wisc.edu/ It sinks!
9 http://www.popsci.com Density of ice at melting point: 3 (0.0 C) H2O -- 916.7 kg m 3 (3.8 C) D2O -- 1105.3 kg m
What properties of water are a consequence of its hydrogen bonded structure? 11 Consequences of hydrogen bonding
1. Anomalous freezing point and boiling point (relative to what?) 12 Boiling points of hydrides 13 Consequences of hydrogen bonding
1. Anomalous freezing point and boiling point (relative to what?) 2. Heat capacity of water 3. Density of ice 4. Surface tension of water 5. "hydrophobic effect" 14 Water on a leaf What is happening here?
15 Effect of ions on water structure 16 Water molecules orientation around a cation
H O H + 17 A cation affects the structure of water to differing degrees depending on the distance. (D) (C) (B) (A) cation 18 A. The primary solvation shell of the cation it contains the water molecules that interact directly with the cation B. The region of secondary solvation. Here the cation has a influence over water molecules. Its electron withdrawing effect on the primary waters of hydration encouraging them to hydrogen bond to secondary waters of hydration C. Disordered region. The magnitude of this region depends on the cation D. Bulk water
What do you think the effect of this will be on the density of salt solutions? 20 Web sites
http://www.chem1.com/acad/sci/aboutwater.html http://www.lsbu.ac.uk/water/index2.html 21 ...
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- Spring '08