Standard Enthalpy Changes

Question 1

How do we determine enthalpy changes?

Answer 1

= under standard conditions

Question 2

What is standard conditions?

Answer 2

= 298 K
= 100 Kpa
= 1 mol/dm^3
= standard states- solid, liquid and gases
= unit: kj mol-1

Question 3

What is standard enthalpy change of combustion?

Answer 3

= enthalpy change when 1 mole of a substance reacts with oxygen under standard conditions and standard states
= we cant change the moles of the reactant

Question 4

What is standard enthalpy change of formation?

Answer 4

= enthalpy change when 1 mole of a compound is formed from it’s elements under standard conditions and standard states