5. Entropy

• Define entropy 


  Measurement of disorder
• How do we represent entropy ?

  S
• The more disorder there is the ….. the level of entropy 


  Higher
• As states change from solid to gas, does entropy increase?


  yes
• Why is entropy lowest at solids ?

  Particles vibrate in arranged neat rows
• What can be determined from this graph abound entropy while changing states ?

  • Gas>liquid> solid
  • Entropy increase by temperature
  • Big increase when changing states ( melting/boiling)
  • Entropy change for liquid to gas is greater than solid to liquid

  
• Why is the entropy larger as you change states?

  The higher the temperature, the faster the particles vibrate and move so greater the entropy(disorder)
• How does entropy between different sized molecules compare ?

  Increase in molecule size = more entropy as more bonds and more atoms so more disorder resulting in an increase in entropy
• How does entropy compare with different ionic bonding?

  Depends on strength of ionic bonding

  • The stronger the ionic bonds = lower the entropy
  • The weaker the ionic bonds = the stronger the entropy
• How does entropy compare when compound is dissolved in a solvent?

  Increase as there is an increase in randomness
• What is larger enthalpy or entropy ?

  Enthalpy is larger as it is measured in KJ and entropy is measured in J
• What is the units for entropy (S)?

  JK-1mol-1
• What is the equation for finding entropy ?

  Sum of products - sum of reactants