Properties of Water

HideShow resource information
  • Created by: SYusuf
  • Created on: 26-10-15 16:19
View mindmap
  • Water
    • Latent Heat of Vaporisation
      • The energy required to transform a given quantity of water from a liquid to a gas.
        • Because the molecules are held together by hydrogen bonds a lot of energy is needed to of water molecules to evaporate
          • Therefore water is useful to cool down living organisms to maintain homoeostasis
            • Plants are cooled when water evaporates from mesophyll cells in transpiration
            • Humans sweat to cool down their body temperature
    • Liquid
      • Hydrogen bonds are constantly broken and remade when water molecules move in liquid.
        • These bonds make it difficult for the molecules to escape as gas. Other molecules of similar size (such as H2S) are gas at room temperature.
          • Because water is liquid at room temperature it is able to:
            • Provide a medium for chemical reactions
            • Form a major component of living tissues
            • Provide a medium for transport e.g in blood plasma
            • Provide a habitat, e.g. in rivers, lakes and seas.
    • Density
      • The density of water is perfect for aquatic organisms to be able to float.
      • Unlike most liquids which become more dense when they cool, water becomes less dense between 4-0 degrees. This allows ice to float on top of water.
        • Aquatic animals have a stable environment to live in the winter (under and atop the layer of ice)
        • Bodies of water are insulated against extreme cold by a layer of ice which reduces the rate of heat loss.
    • Solvent
      • Water is a good solvent for ionic molecules and covalent molecules.
        • Because water is polar it is attracted to the  slightly charged parts of the solutes. They cluster around these charged parts and will separate them and keep them apart.
          • This helps molecules and ions move around and react together in water e.g in the cytoplasm
          • This also helps molecules and ions to be transported around the body while dissolved in water/
    • Cohesion & Surface Tension
      • Hydrogen bonding pulls water molecules together
        • This causes them to stick together (cohere) instead of spreading out
        • This also means that water contracts as molecules on the surface are pulled inwards by hydrogen bonds to molecules beneath.
          • This means water is able to resist force applied to it, this property is known as surface tension.
            • This allows:
              • Columns of water in plant vascular tissue to be pulled up the xylem together from the roots.
              • Insects like pond skaters to walk on water.
    • Specific Heat Capacity
      • The amount of energy needed to raise the temperature of 1 kg of water by 1 degree celcius.
        • Due to hydrogen bonds water has a high SHC of 4.2 kJ. This means it does not heat up or cool down easily
          • Because the main component of living organisms is water this makes it easier to maintain a constant temperature needed for enzyme controlled reactions.
    • Reactant
      • Water is important for the digestion of large biological molecules (such as starch, proteins and lipids) through hydrolysis.
      • Water is a reactant in photosynthesis which is important for the synthesis of glucose
  • A lot of water's properties are due to its polar nature, which allows for the formation of hydrogen bonds



Heya, can anyone tell me any good websites to create mind maps?

Similar Biology resources:

See all Biology resources »See all Biological molecules resources »