Properties of Water

• Water's properties result from its polar nature and ability to form hydrogen bonds
• Oxygen is more electronegative than hydrogen
• Hydrogen bonds are weaker than covalent bonds because electrons are not shared
• Cohesion


  tendency of water molecules to stick together - result of hydrogen bond
• Adhesion is the tendency of water molecules to be attracted to other molecules
• High surface tension allows some things to exist on the surface of water
• Capillary action facilitates movement of liquids in narrow spaces like tubes
• excellent solvent


  when mixed with other compounds, water almost always dissolves them
• Excellent solvent


  Water breaks existing bonds between atoms within molecules because of its polar nature and thus dissolves them
• high specific heat


  Water can store and absorb significant amounts of heat without experiencing significant changes in temperature
• high heat of vaporization


  Quantity of heat a liquid must absorb for 1 g of it to be converted from liquid to gas.
• high heat of vaporization

  as liquid evaporates, the surface of the liquid that remains behind cools down
• lower density as solid than liquid


  Water molecules constantly move because of hydrogen bonding as liquid but freeze up and are spread farther apart in solid form
• water is most dense at 4 degrees celsius
• cohesion

  • allows water to remain liquid at room temperature and resists temperature changes
  • allows transportation of nutrients and wastes in molecules
  • transport of water from the roots to leaves of plants
• adhesion

  • facilitates the movement of water in plant tissues, helping to transport nutrients and water from the roots to other parts of the plant
  • adhesion of the water molecules in blood to the walls of blood vessels helps in the circulation of blood throughout the body
  • allows water to wet surfaces, allows it to spread out and form thin films; important for processes like the absorption of water by soil and the wetting of cell membranes
• high surface tension

  • Allows formation of water droplets
  • Enables retention of cellular integrity
• capillary action

  • Lets water move up stems of plants
  • Water sticks to the walls of the plant stem and to each other thanks to adhesion and cohesion and when the water at the top is evaporated, it enables transport of vital nutrients
  • Helps blood travel in blood vessels
  • Enables gas exchange
  • Allows for nutrient distribution in soil
• excellent solvent

  • Allows for transport of nutrients because it takes dissolved substances with it as it moves
• high specific heat

  • Enables temperature regulation in organisms and bodies of water
  • Thus facilitates homeostasis regarding temperature in living things
  • Allows precipitation, evaporation, and condensation
• high heat of vaporization

  • Allows climate moderation
  • temperature regulation (sweating in some animals)
  • thermal stability
• lower density as solid than liquid

  • Prevents complete freezing of water
  • In large bodies of water, only surface freezes over and lets aquatic organisms survive during cold periods
  • Makes bodies of water freeze from the top down
• soap decreases cohesion and surface tension
• soap has a polar head
• the negative charge of soap of soap is attracted to the partially positive hydrogen of water
• the positive charge of soap is attracted to the partially negative oxygen of water