water and its functions Flashcards
what is a hydrogen bond
attraction between negative pole of one water molecule and positive pole of another water molecule
what is the strength of a hydrogen bond
individual bonds much weaker than a covalent bond
together they form important forces that cause water molecules to stick together
why is water a polar molecule
has a positive charge where the hydrogen is and. a negative charge where the oxygen is
what are the five qualities of water due to polarity
cohesion and surface tension
latent heat of vaporisation
high specific heat capacity
good solvent
density
why does water have a high specific heat capacity
requires a lot of energy to change the temperature
why does water act as a buffer against rapid temperature changes
heat energy goes towards weakening or breaking hydrogen bonds not increasing kinetic energy of water molecules
what is the benefit of water acting as a buffer to rapid temp changes
allows water to act as an aquatic habitat
what is the benefit of ice being less dense than liquid water
ice insulates water below and prevents it from freezing
why does water have a large latent heat of vaporisation
takes a large amount of heat energy to evaporate water
what is the benefit of large latent heat for organisms
allows organisms to cool themselves without using a large amount of energy.
how does sweating help organisms cool down
heat energy used to evaporate water from surface of skin
transfer of energy allows organism to cool down
what does water being an excellent solvent mean
many substances can dissolve in it
what is the benefit of water being an excellent solvent
can be used to transport substances (eg in blood plasma or xylem vessels)
what does cohesion and adhesion mean
water molecules tend to stick together
what is the benefit of the cohesion and adhesion
water has large cohesive forces and these allow it to be pulled through a tube such as a xylem vessel in plants
