water Flashcards
universal solvent importance
-allows chemical reactions to occur inside cells
-capable of dissolving more substances than any other liquid due to polarity and ability to make hydrogen
high latent heat of vaporisation
-constant temp
-more energy required to break bonds
capillary actiom
allows a continuous column of water to move through xylem
high SHC
-constant temp
-stabilising for aquatic environments
-more energy needed to change water temp
surface tension
due to hydrogen bonds which means light creatures can walk on it eg. pond skaters
how is water polar
-oxygen acts as negative, hydrogen acts as positive so opposites attract and create polar covalent bonds
-uneven charge in molecule
what does polar mean
an uneven distribution of charge within a molecule
how do water molecules bond to each other
-hydrogen bond between oxygen and other molecule’s hydrogen
-easy to bond due to positive H and negative O
how do water molecules bond within themselves
covalent bond-share electrons
cohesion
water molecules stick to each other through hydrogen bonds so columns of water can rise up narrow tubes
eg. water evaporates from leaf and takes next molecule with it
adhesion
water molecules stick to other substances
what happens when water freezes
-water expands when it freezes and becomes less dense so floats on top
-molecules are further apart, so are less dense
-lattice structure
why is it useful that ice is less dense?
forms on surface of lakes and insulated water below so aquatic animals dont freeze and can still move to retrieve nutrients
which features would be just as useful for prokaryotes?
-universal solvent as reactions must occur readily
-lot of energy to change temp as it creates a more stable environment
what does water act as a solvent for?
ions such as nitrates (bind to water)
