hydrogen bonding and water Flashcards
water has unique properties
molecule has no overall charge
oxygen atom carries slight negative charge
hydrogen atoms carry slight positive charges
polarity attracts them to one another
what has no overall charge?
molecules
what atom carries slight negative charge?
oxygen
what atoms carry slight positive charges?
hydrogen
what attracts them to one another?
polarity
what is a hydrogen bond?
an attraction between a covalently bonded hydrogen atom and another atom taking part in a separate polar covalent bond
is a hydrogen bond a chemical bond?
not a chemical bond
what does a hydrogen bond form?
a hydrogen bond forms and breaks more easily than covalent or ionic bonds
is a hydrogen bond weak or strong?
a hydrogen bond is collectively quite strong
what gives liquid water special properties?
extensive hydrogen bonding
makes life possible
water is an excellent solvent that allows other substances to do what?
dissolve in it (water)
what are the 2 special properties of water?
hydrophilic and hydrophobic
hydrophilic
water-loving
hydrophilic substances dissolve easily in water
what’s a solution?
a uniform mixture
what’s an example of a solution?
salt dissolved in water
what may vary in a solution?
proportions of substances
hydrophobic
water-dreading
do hydrophobic substances interact with water?
no, hydrophobic substances do not interact with water
what’s an example of something hydrophobic?
oils
what is concentration?
the amount of solute dissolved in a given fluid amount
what is cohesion?
hydrogen bonds collectively exert a continuous pull on individual water molecules
cohesion plays a role in what?
surface tension
what is evaporation?
water molecules escape from liquid water surface as vapor
what is evaporation resisted by?
hydrogen bonding
cohesion of water molecules provides what that enables an insect to be able to walk on water?
surface tension
what is temperature?
the measure of the energy of motion of atoms & molecules
what stabilizes temperature?
water
what keeps water molecules from moving as much as they would?
hydrogen bonding
what is the important part of homeostasis?
temperature stability
what is temperature stability?
molecules of life function within certain range of temperature
what molecules pack less densely on ice than they do in water; reason why ice floats on water?
individual water molecules
