Water And Inorganic Ion Flashcards
What is electo-negativity?
The measure of an atoms pull on a bonded pair of electrons
Why are water molecules dipolar?
The bonded pairs of electrons are slightly more attracted to the positive nucleus of oxygen so the hydrogen end is slightly positive
What type of bonding occurs WITHIN water molecules?
Covalent bonds
What bonding occurs between water molecules?
Hydrogen bonds
Name all the properties of water?
- Cohesion
- Adhesion
- Transparent
- High specific heat capacity
- High specific latent heat of vaporisation
- Metabolite
- Solvent
- Ice (Density)
Why are water molecules cohesive?
Water molecules are cohesive due to the hydrogen bonding between them.
The slightly negative oxygen end is attracted to the slightly positive hydrogen end of another water molecules
How does cohesion aid living organism?
Cohesion creates surface tension which supports small organisms like pond skaters on the surface
Cohesion between molecules helps support continuous columns of water in the xylem (transpiration stream)
How does adhesion aid living organism?
Adhesion occurs between water and another polar substance
It allows for capillary action in the stem of plants as it facilitates movement up the walls of the xylem vessel
How does transparency of water aid living organism?
It allows light to penetrate and means aquatic plants can photosynthesise
Why is water a good solvent?
Water is a polar molecule which makes it a universal solvent
This means ionic and other polar molecules can dissolve in it for transportation (eg. Slat/amino acids)
Also chemical reactions occur more quickly in solution
How does the property of being a metabolite make water useful?
It allows for hydrolysis and condensation reactions (eg. In ATP)
Why does ice float?
When water freezes it expands as the hydrogen bonds hold the water molecules further apart. Therefore making it less dense that water so floats
Why is ice floating a useful property?
It prevents freezing of water below and allows aquatic organisms to survive below
Why does water have a high latent heat of vaporisation ?
A lot of energy is required to break the hydrogen bonds between the water molecules
Why is high latent heat of vaporisation useful?
It acts as a thermal regulatory mechanism for organism.
For example when we sweat lots of our heat energy is released when it is used to evaporate the water, which helps provide a cooling effect.
