1.7 Water Flashcards
What are the 3 uses of water
- Reactant in cells (e.g. hydrolysis)
- Provides structural support
- Keeping organisms cool to maintain optimum body temperature
The 5 special properties of water
- Metabolic Importance
- High heat capacity
- Heat of vaporisation
- Cohesive properties
- Useful as a solvent
Why is water a polar molecule?
The O atoms are slightly -VE
The H atoms are slightly +VE
What is hydrogen bonding?
Where a H atom on one water molecule is attracted to the O atom on another molecule
What is the name for the strong attraction between H2O molecules due to H bonds
cohesion
What does cohesion produce and where
Cohesion produces surface tension when water meets air
What phenomenon do plants use to help transport water from the roots to their leaves
surface tension
What is the latent heat of vaporisation?
The amount of energy needed to change one gram of a liquid substance to a gas
Why does water have a high heat of vaporisation
Hydrogen bonding makes it difficult to separate the water molecules from eachother - this means a lot of energy is needed for H2O to evaporate
What happens when H2O evaporates
energy is used up - cooking the environment around it
What is meant by water being a good metabolite
water is used / formed in many metabolic reactions such as condensation or hydrolysis
Why is water a good solvent
ions and polar molecules can easily dissolve in it
What is specific heat capacity?
the amount of heat one gram of a substance must absorb or loose to change its temperature by 1C
does water have a high or low heat capacity
high heat capacity so it takes a long time to heat and cool
define waters property of cohesion
the intermolecular force between water molecules
