ENTHALPY CHANGE

• EXAMPLES OF ENDOTHERMIC REACTIONS?

  • decomposition (thermal)
  • photosynthesis
  • acid + metal carbonate
• EXAMPLES OF EXOTHERMIC REACTIONS?

  • respiration
  • combustion
  • neutralisation
• WHERE DO THE ELECTRONS GO IN A REDUCTION HALF EQUATION?

  reactants
• WHERE DO THE ELECTRONS GO IN AN OXIDATION HALF EQUATION?

  products
• WHAT IS AN ENTHALPY CHANGE?

  amount of heat energy taken in/ given out during any change in a system provided pressure is constant
• SYMBOL FOR ENTHALPY CHANGE?

  ΔH
• WHAT IS ENTHALPY CHANGE MEASURED IN?

  kJmol^-1
• WHAT ARE THE STANDARD CONDITIONS?

  • 100 kPa
  • 298 K
  • solutions at 1 moldm^-3
• WHAT ARE THE STANDARD CONDITIONS OF PRESSURE?

  100 kPa (1 atm)
• WHAT ARE THE STANDARD CONDITIONS OF TEMPERATURE?

  298 K (25 degrees Celsius/ room temperature)
• WHAT ARE THE STANDARD CONDITIONS OF SOLUTIONS?

  1 moldm^-3
• WHAT ARE THE TYPES OF ENTHALPY CHANGE?

  formation, combustion
• WHAT IS THE ENTHALPY CHANGE OF FORMATION?

  enthalpy change that occurs when one mole of the compound is formed from its elements under standard conditions (100 kPa, 298 K) with all reactants and products being in their standard form
• WHAT IS ENTHALPY CHANGE OF COMBUSTION?

  enthalpy change which occurs when one mole of the compound is burned completely in oxygen under standard conditions (100 kPa, 298 K) with all reactants and products being in their standard states