Water Flashcards
(10 cards)
what are the cohesive properties of water
molecules of the same type (water) are attracted to each other
what is hydrogen bonding
electrostatic force of attraction between a hydrogen atom covalently bound to a more electronegative atom or group
gives water its unique properties
what are the adhesive properties of water
any attraction between two unlike molecules
- capillary action: transport of water up vascular column via transpiration stream involves both cohesion (water - water) and adhesion (water - cellulose)
what are the thermal properties of water
high specific heat capacity: amount of energy required to raise the temperature of water is high due to hydrogen bonds
high latent heat of vaporisation: heat energy required to evaporate water is relatively high (cooling effect)
high boiling point
what are the solvent properties of water
polar nature of water: forms shells around other polar molecules which dissolves them and keeps them in solution (cytoplasm)
what are some examples of water as a solvent in plants and animals
water medium of transport in vascular tissue:
- xylem carries water and dissolved sugars from leaves to stem/roots/flowers of a plant
blood as a medium of transport in animals:
- blood plasma: liquid portion of blood/carries solutes such as glucose/amino acids/fibrinogen/hydrogen carbonate ions
what happens to covalent and ionic molecules in water
ionic molecules: dissociate (separate into ions)
polar covalent: dissolve (molecules stay together and bond with water)
non polar covalent: does not dissolve (repels and forms layers)
what are hydrophilic and hydrophobic substances
hydrophilic: chemically attracted to water
hydrophobic: non polar and not attracted to water
what makes water have a polar covalent bond
unequal sharing of electrons between O and 2H
H atoms slightly positive and O atom slightly negative
what is the significance of water
required for anabolic construction of organic molecules via condensation
essential to acid-base neutrality and enzyme function