Water Flashcards
Why is water so important?
It can synthesise and break down biological molecules and is a key reactant
What type of bonds are in water molecules?
Covalent bonds
What bonds form between water molecules and why?
Hydrogen bonds as water is polar
Why is it important that water has a high boiling point?
It is a habitat for aquatic organisms, it is a chemical reaction and transport medium
Why does water have a high specific heat capacity?
More energy is needed to break the hydrogen and covalent bonds
Why is it important that it has a high specific heat capacity?
Lakes etc. stay a stable temperature and water in cells is a stable environment for enzymes
Why does water have a high latent heat of vaporisation?
To evaporate, the hydrogen bonds break from lots of heat energy. when water evaporates, it takes heat energy from its surroundings
How is water evaporation helpful for organisms?
Sweating is a cooling mechanism, and plants can also be cooled from water evaporation from the leaves
What is cohesion?
The attraction between molecules of the same type
When is cohesion used?
Xylem vessels - water molecules follow behind each other in a continuous stream
What other property is due to cohesion?
Surface tension - so pond skaters can have a habitat
As water is a solvent, it can be used as a transport medium for which solutes?
Gases, polar biological molecules, inorganic ions
Why is ice unusual?
It is less dense than water because the molecules have gaps between them as they are polar
