Energetics Flashcards
Define activation energy
The minimum amount of energy required to initiate a reaction
Define enthalpy
The heat content stored within a chemical system
Define the enthalpy change of neutralisation
The enthalpy change when 1 mole of water is produced from the reaction between an acid and an alkalai in standard conditions with reactants and products in standard states
Define average bond enthalpy
The average enthalpy change required to berak one mole of a specified bond in gaseous molecules
How can change in enthalpy be measured
Calorimetry, where the substance is burned and the temperature change of usually water is measured.
Mixing reactants together in solvent and measuring the temperature change.
Define enthalpy change of solution
The enthalpy change when one mole of an ionic solid dissolves in an amount of water large enough so that the dissolved ions are well separated and do not interact with each other.
Define enthalpy change of hydration
The enthalpy change when one mole of gaseous ions becomes hydrated
How is enthalpy change of solution calculated
Hydration - Lattice.
If Hsol is negative, the substance is soluble in water.
What is the equation for Gibbs Free Energy, and what does it mean
DG=DH-TDS(*0.001)
A reaction is feasible at the given temperature when this has a negative value.
How do you calculate the minimum feasible temperature for a reaction to occur
Tmin = DH/DS*0.001
How to calculate enthalpy change
Q=mcΔt
