A LEVEL CHEMISTRY ENTHALPY
DEFINITIONS EXAM QUESTIONS AND
ASNWERS
Average bond enthalpy - ANSWER-The energy required to break one mole of a
specified type of bond in a gaseous molecule.
Lattice enthalpy - ANSWER-The enthalpy change that accompanies the formation of
one mole of an ionic compound from its gaseous ions under standard conditions
Standard enthalpy change of atomisation - ANSWER-The enthalpy change that
takes place for the formation of one mole of gaseous atoms from the element in its
standard state under standard conditions.
First ionisation energy - ANSWER-The enthalpy change required to remove one
electron from each atom in one mole of gaseous atoms to form one mole of gaseous
1+ ions.
First electron affinity - ANSWER-The enthalpy change that takes place when one
electron is added to each atom in one mole of gaseous atoms to form one mole of
gaseous 1- ions.
Standard enthalpy change of solution - ANSWER-The enthalpy change that takes
place when one mole of a solute completely dissolves in a solvent under standard
conditions.
Standard enthalpy change of neutralisation - ANSWER-The enthalpy change that
accompanies the reaction of an acid by a base to form one mole of H20 (l), under
standard conditions, with all products and reactions in their standard states.
Enthalpy change of hydration - ANSWER-The enthalpy change that accompanies
the dissolving of gaseous ions in water to form one mole of aqueous ions.
Standard enthalpy change of reaction - ANSWER-The enthalpy change that
accompanies a reaction in the molar quantities shown in a chemical equation under
standard conditions, with all products and reactants in their standard states.
Standard enthalpy change of formation - ANSWER-The enthalpy change that takes
place when one mole of a compound is formed from its elements under standard
conditions, with all products and reactants in their standard states.
Standard enthalpy change of combustion - ANSWER-The enthalpy change that
takes place when one mole of a substance reacts completely with oxygen under
standard conditions, with all products and reactants in their standard states.
DEFINITIONS EXAM QUESTIONS AND
ASNWERS
Average bond enthalpy - ANSWER-The energy required to break one mole of a
specified type of bond in a gaseous molecule.
Lattice enthalpy - ANSWER-The enthalpy change that accompanies the formation of
one mole of an ionic compound from its gaseous ions under standard conditions
Standard enthalpy change of atomisation - ANSWER-The enthalpy change that
takes place for the formation of one mole of gaseous atoms from the element in its
standard state under standard conditions.
First ionisation energy - ANSWER-The enthalpy change required to remove one
electron from each atom in one mole of gaseous atoms to form one mole of gaseous
1+ ions.
First electron affinity - ANSWER-The enthalpy change that takes place when one
electron is added to each atom in one mole of gaseous atoms to form one mole of
gaseous 1- ions.
Standard enthalpy change of solution - ANSWER-The enthalpy change that takes
place when one mole of a solute completely dissolves in a solvent under standard
conditions.
Standard enthalpy change of neutralisation - ANSWER-The enthalpy change that
accompanies the reaction of an acid by a base to form one mole of H20 (l), under
standard conditions, with all products and reactions in their standard states.
Enthalpy change of hydration - ANSWER-The enthalpy change that accompanies
the dissolving of gaseous ions in water to form one mole of aqueous ions.
Standard enthalpy change of reaction - ANSWER-The enthalpy change that
accompanies a reaction in the molar quantities shown in a chemical equation under
standard conditions, with all products and reactants in their standard states.
Standard enthalpy change of formation - ANSWER-The enthalpy change that takes
place when one mole of a compound is formed from its elements under standard
conditions, with all products and reactants in their standard states.
Standard enthalpy change of combustion - ANSWER-The enthalpy change that
takes place when one mole of a substance reacts completely with oxygen under
standard conditions, with all products and reactants in their standard states.
