3.2 Water Flashcards
State the different properties of water which make it suited for sustaining life:
- POLAR
- HIGH SPECIFIC HEAT CAPACITY
- HIGH LATENT HEAT OF VAPORISATION
- METABOLITE
- STRONG COHESION
- ICE IS LESS DENSE THAN WATER
How does being polar help make water especially suited for sustaining life?
Acts as polar solvent
Cytosol of cells are mostly H2O, in order to dissolve polar solutes
so that reactants can collide
How does water being a metabolite make it well suited for sustaining life?
Required in condensation & hydrolysis
used for making & breaking bonds in chemical reactions
How does water having a high specific heat capacity make it well suited for sustaining life?
Lots of energy required to increase temperature
bodies of water remain at fairly constant temperature
stable environment for aquatic organisms
How does water having a high latent heat of vaporisation make it well suited for sustaining life?
Requires a lot of energy to vaporise
provides efficient cooling mechanism
How does water having strong cohesive forces make it well suited for sustaining life?
Allows for capillary action
for xylem & phloem vessels within plants
How does ice having a lower density than water make it well suited for sustaining life?
Ice sheets float on water
trap insulating layer of air
maintains temperature of water beneath for stable habitat
How does hydrogen bonding occur within water molecules?
Water is polar, has Oδ- & Hδ+
negative lone pair of electrons on Oδ- attracted to Hδ+ of another water molecule
electrostatic attraction = hydrogen bond
Why is ice less dense than water?
When water cooled, molecules condense until 4°C
below 4°C, molecules have little enough energy for hydrogen bonds to form & not be instantly broken by molecules moving apart
holds water molecules apart, creating crystalline open lattice structure
which is less dense than water
