water Flashcards
why is water important?
1) it is a reactant in many chemical reactions(eg hydrolysis
2) Water is a solvent (most reactions take place in an solvent)
3) transports substances
4) helps with temperature control- as it has a high SHC and high latent heat of evaporation
5) it is a habitat: many organisms can survive and reproduce in it
PERFECTO
what are the slight charges of the oxygen and hydrogen on a water molecule
O delta negative
H is delta positive
making water a polar molecule
how to describe hydrogen bonding?
when a slightly negatively charged oxygen atom is attracted to a slightly positive hydrogen atom
what is specific heat capacity
and why does water have a HSC
the amount of energy needed to raise the temperature of a 1 gram substance by one degree
This is because hydrogen bonds in the water molecules can absorb a lot of energy
Why is water a good habitat
Because
it doesn’t experience rapid temperature change
what is high latent heat of evaporation
why does water have a HLHOE
amount of energy required to change the state of a 1 gram substance.
This is because it takes a lot of energy to break the hydrogen bonds (so a lot of energy is used when water evaporates)
why is having a HLHOE good for living organisms
great for cooling things
when sweat evaporates it cools the surface of the skin
what does cohesive mean
why is water cohesive
and why is this a good property of water
DEF: attraction between molecules of the same type
water is cohesive because it is polar
it is good that water is cohesive because its great for transporting substances ( eg up plant stems in transpiration stream)
why is ice less dese than water
This is because water molecules are further apart in ice than they are in liquid water, because each water molecule forms 4 Hbonds (making a lattice shape)
which is why ice floats
how can ice be useful to living organisms in cold temperatures
Ice forms an insulating layer on top of the water- so water below doesnt freeze. so fish dont freeze and can still move around
