Enthalpy Flashcards
Define enthalpy change
This is the heat energy released or taken in at a constant pressure
Define exothermic reactions
The temperature goes up
Heat energy is released
Negative enthalpy change
Define endothermic reactions
The temperature goes down
Heat energy is taken in
Positive enthalpy change
Describe the exothermic and endothermic graphs
Check your answer using the booklet, I’m not paying for pro sorry
Describe the exothermic and endothermic graphs
Check your answer using the booklet, I’m not paying for pro sorry
Define the ‘Standard Enthalpy Change of Formation’
This is the enthalpy change that occurs when one mole of a compound is formed from its constituent elements in their normal physical states under standard conditions of temperature and pressure
Define the ‘Standard Enthalpy Change of Combustion’
This is the enthalpy change that occurs when one mole of compound is completely burnt in oxygen under standard conditions
Define the ‘Standard Enthalpy Change of Combustion’
This is the enthalpy change that occurs when one mole of compound is completely burnt in oxygen under standard conditions
Define ‘Hess’s Law’
The enthalpy change of a chemical reaction is independent of the route taken provided that the initial and final states are the same
What are the ‘Standard Conditions’
298K
1 atm pressure
Define ‘Bond Enthalpy’
This is the energy absorbed to break one mole of bonds
To undertake any chemical reaction, reactants have to combine and form products. Therefore, in order to allow a reaction to occur we have to break and make bonds.
Describe why bond breaking requires energy
Energy has to be taken in from the surroundings.
Describe why bond breaking requires energy
Energy has to be taken in from the surroundings.
Describe why bond breaking requires energy
Energy has to be taken in from the surroundings.
Describe why bond breaking requires energy
Energy has to be taken in from the surroundings. Therefore, bond breaking is an endothermic process
