Chemical Energetics Flashcards
Hess’ Law
The enthalpy change accompanying a chemical reaction is the same REGARDLESS OF THE ROUTE by which the chemical change occurs, provided the INITIAL AND FINAL STATES ARE THE SAME.
STANDARD enthalpy change of reaction
The energy change in a chemical reaction when MOLAR QUANTITIES OF REACTANTS specified in the chemical equation react to form products at STANDARD CONDITIONS
Standard enthalpy change of formation of substance (this feels like the more general one to me because it could be any substance)
The energy change when ONE MOLE OF THE SUBSTANCE is formed from its CONSTITUENT ELEMENTS under standard conditions.
Standard enthalpy change of combustion a substance
Is the energy evolved when one mole of a substance is COMPLETELY BURNT IN OXYGEN under standard conditions.
Standard enthalpy change of neutralisation
Is the energy evolved when ONE MOLE OF WATER is formed from the neutralisation between an acid and a base under standard conditions. (omg neutralisation is exothermic)
Standard enthalpy change of atomisation of an element
Is the energy ABSORBED when one mole of gaseous ATOMS is formed from the element under standard conditions.
Bond energy
The AVERAGE energy that is absorbed to break one mole of covalent bonds in the GASEOUS STATE to form GASEOUS ATOMS under standard conditions.
Bond dissociation energy
The energy required to break ONE MOLE OF A PARTICULAR COVALENT BOND in a SPECIFIC MOLECULE in the gaseous state to form gaseous atoms.
Lattice energy of an ionic solid
Energy evolved when one mole of a SOLID IONIC COMPOUND is formed from its constituent GASEOUS IONS under standard conditions.
First ionisation energy
The energy absorbed when one mole of GASEOUS atoms loses one mole of electrons to form one mole of singly charged GASEOUS cations.
Second ionisation energy
The energy absorbed when one mole of singly charged gaseous cations loses one mole of electrons to form one mole of doubly charged gaseous cations.
First electron affinity
The energy released when one mole of gaseous atoms acquires one mole of electrons to form one mole of singly charged gaseous anions.
Second electron affinity
The energy absorbed when one mole of singly charged gaseous anions acquires one mole of electrons to form one mole of doubly charged gaseous anions.
Standard enthalpy change of hydration of an ion
Energy EVOLVED when one mole of gaseous ions is HYDRATED under standard conditions.
Standard enthalpy change of solution of a substance
Energy change when one mole of a substance is completely dissolved in a solvent to form an INFINITELY DILUTE SOLUTION under standard conditions.