Water Flashcards
What charge does water have?
no overall charge.
What charge does the oxygen in water have?
slightly negative charge.
What charge does the hydrogen in water have?
slight positive charge.
Why is water described as dipolar?
because it has both a slight positive and slight negative charge.
How are water molecules attracted to each other?
What are these forces called (bond) ?
the positive pole of 1 water molecule will be attracted to the negative pole of another water molecule.
the attractive forces between these opposite charges are called hydrogen bonds.
Are hydrogen bonds weak or strong?
hydrogen bonds are weak individually, but together they form important forces that cause water molecules to stick together.
Why does water have a high specific heat capacity?
because water molecules stick together, it takes more energy to separate them than would be needed if they did not bond together.
Water acts as a … against sudden temp changes
Water acts as a buffer against sudden temp changes
Why does water have a high latent heat of vaporisation?
hydrogen bonding between water molecules means that it requires a lot of energy to evaporate 1g of water.
What is cohesion?
The tendency of water molecules to stick together.
What gives water its large cohesive forces?
Hydrogen bonds
What do the large cohesive forces in water allow it to do?
The large cohesive forces allow water to be pulled up through a tube.
What is surface tension?
The force with which the surface molecules are held together.
Why is water important in metabolism? (4)
- Water is used to break down many complex molecules through hydrolysis.
- Water is produced i condensation reactions.
- Chemical reactions take place in a aqueous medium.
- Water is a major raw material in photosynthesis.
Why is water important as a solvent?
Water readily dissolves substances:
gases - O2 and CO2
wastes such as ammonia and urea
inorganic ions and small hydrophilic molecules such as amino acids
enzymes whose reactions take place in solution.
