Molecular properties

• Water molecules

  Held together via STRONG hydrogen bonds
• VSEPR Theory

  Describes shapes of molecules
• What does VSEPR stand for

  Valence shell electron pair repulsion
• What does water dissociate into

  
  

  Hydroxide ions and Hydronium ions.
• What is Kw


  
  

  
  

  Water dissociation constant
• Give the equation for Kw

  Kw = [OH-][H3O+]
• Properties of water

  • High boiling point
  • High Cohesion
  • High heat of vaporisation
  • Ice is less dense than water
  • High specific heat capacity [4.18 J]
  • Good solvent for polar/ionic substance
• What causes the high boiling point of water

  
  

  Hydrogen bonds
• Why is ice less dense than water

  Ice has 4 bonds per molecule and so has a more open structure
• What is the meaning of specific heat capacity [4.18 J]

  4.18J is required to heat 1g of water by 1C
• Why is water a good solvent for polar/ionic substance

  As it either forms H-bonds or hydrates ions
• What is the unit for molecular mass

  Daltons
• What is the equation for concentration

  Moles / Volume
• What is pH

  Measure of the concentration of H+ ions
• pH equation

  pH = -log [H+]
• [H+] equation

  10 ^ -pH
• What is Avagador's number

  6.02 x 10 ^23
• What is the equation for moles using avagadros number

  
  

  particles / 6.02*10^23
• What is the value of Kw

  1*10^-14
• What is the equation for mass

  Mass = Moles * Mr [Ar]