1. structure of water

• Why is water considered a polar solvent?

  It can dissolve many biological molecules
• What property of water enables effective transport through xylem vessels?

  Cohesion and adhesion due to hydrogen bonding
• What is the significance of water's high heat specific capacity?

  It minimizes temperature fluctuations in living things
• What is a ‘solvent’?

  A liquid which can dissolve substances in it
• What is a ‘solution’?

  When a liquid has dissolved substances in it
• What state of matter is water?

  Liquid
• How does the state of water relate to its function?

  Easily transports substances
• What percentage of a cell’s contents is water?

  80%
• What are the keywords related to water and transport?

  • Polar
  • Dipole
  • Hydrogen bonding
  • Solvent
  • Hydrophobic
  • Hydrophilic
  • Specific heat capacity
• What is the structure of water molecules?

  Two hydrogen atoms bonded to one oxygen atom
• How are the hydrogen atoms positioned in a water molecule?

  They are angled around the oxygen atom
• Where are all the electrons found in a water molecule?

  Shared between hydrogen and oxygen atoms
• What charge will hydrogen have in a water molecule?

  Slightly positive charge
• What charge will oxygen have in a water molecule?

  Slightly negative charge
• What is a dipole in the context of water molecules?

  A molecule with partial positive and negative charges
• What happens when two water molecules are placed together?

  They form hydrogen bonds due to attraction
• What is hydrogen bonding?

  Attraction between positive hydrogen and negative oxygen
• Are hydrogen bonds strong bonds?

  No, they are relatively weak bonds
• What can easily break hydrogen bonds?

  Heating water molecules
• How do hydrogen bonds help stabilize water's structure?

  Many hydrogen bonds form together
• How does the dipole nature of water contribute to its function?

  It allows water to dissolve many substances
• Describe the structure of one water molecule.

  Dipolar molecule with hydrogen bonding
• What are the properties of water and their importance?

  • Cohesion and Adhesion: Helps in transport
  • Solubility: Dissolves many substances
  • Specific heat capacity: Regulates temperature
  • Latent Heat of Vaporisation: Cools organisms
• What is cohesion in water?

  Ability of like molecules to stick together
• What is adhesion in water?

  Ability of unlike molecules to stick together
• What happens when water is exposed to NaCl?

  Sodium and chloride ions become hydrated
• Why is it important for polar molecules to dissolve in water?

  Facilitates transport in organisms
• What is the specific heat capacity of a material?

  Energy to raise 1kg by 1°C
• What is the latent heat of vaporisation of a material?

  Energy to change 1kg from liquid to gas
• What is avoided in thermal properties of water?

  Rapid temperature changes
• Why is the latent heat of vaporisation useful for organisms?

  It helps cool organisms through evaporation
• Explain how the dipolar nature of water is essential for living organisms.

  It allows water to dissolve nutrients and transport them
• What are the thermal properties of water and their significance?

  • High specific heat capacity: Stabilizes temperature
  • High latent heat of vaporisation: Cools organisms
• explain the dipole nature of water

  The oxygen is slightly negative and the hydrogen is slightly positive. The shared electrons are being pulled towards oxygen.
• Where is cohesion and adhesion?

  Cohesion is the attraction between like molecules

  Adhesions the attraction between unlike molecules
• Specific heat capacity


  The amount of energy needed to raise 1 kg by substance by 1°
• What is the importance of Latent heat of vaporisation?

  To allow organisms to cool down when sweating as it takes the energy with it
• Polar

  When the electrons do not have an equal distribution of electrons in the orbit
• Dipole

  A molecule that has a partial negative charge and partial positive charge
• Hydrogen bonding in water

  Hydrogen bonds are not strong bonds.

  Heating can easily break hydrogen bonds (example when water molecules move apart becoming a gas) 

  However many thousands of hydrogen bonds conform and this helps to stabilize a structure of the molecule