Water Flashcards
Water is a polar molecule what does this mean
This means that the molecule has an even distribution of charge- the oxygen is more negative than the hydrogens as the electrons are drawn towards the oxygen and away from the hydrogen.
Water has a relatively large latent heat of vaporisation what does this mean
Providing cooling effect with little loss of water through evaporation
Water is polar,how does this affect its significance for life
This makes it a good solvent
It dissolves polar molecules and ions
All reactions take place in solution
It is reactive and is a metabolite in condensation and hydrolysis reactions
Acts as a transport medium as some chemicals dissolve in it e.g. blood,phloem, xylem
Strong cohesive properties and high tensile strength,,how does this have significance for life
Tall columns of water can be drawn up xylem vessels in tall trees (the cohesion tension theory)
High surface tension- allows some organisms to walk on the surface
High latent heat of vaporisation,how does this have significance for life
Allows the body to cool whilst sweating
High specific heat capacity
(Water can absorb a lot of energy only for a small rise in temperature-heats up slowly,cools down slowly)
Prevents large fluctuations in water temperature so,aquatic habitats are thermally stable and so organisms don’t have to endure extremes of temperature.
What charge is oxygen
Oxygen has a small negative charge
What charge do the hydrogens have
A small positive charge
What doe the opposite charges of oxygen and hydrogen make water become?
A polar molecule
What do water molecules do to eachother due to the polar charges and what are these forces called
Attract eachother and these forces are called hydrogen bonds
What are all the properties of water
High specific heat capacity
High latent heat vaporisation
Cohesion
What does it mean if water has a very high specific heat capacity
This means that we have to put in or take out a large amount of energy to change the temperature of water
What happens when we heat water
The energy goes towards weakening or breaking the hydrogen bonds rather than increasing the energy of weak molecules
Because of this water acts as a buffer against rapid temperature changes
Does water change rapidly?
No
What does latent heat vaporisation mean
It takes a large amount of heat energy to evaporate water
