Energetics Flashcards
(15 cards)
Define standard enthalpy change of reaction
The energy change when molar quantities of reactants as specified by the chemical equation react to form products, with all reactants and products in their standard states, at a specified temperature,
usually 298 K.
Define standard enthalpy change of formation
The energy change when 1 mole of a substance in its standard state is formed from its constituent elements in their standard states, at a specified temperature, usually 298 K.
Define standard enthalpy change of combustion
The energy released when 1 mole of a substance is completely burnt in excess oxygen, with all reactants and products in their standard states, at a specified temperature, usually 298 K.
Define standard enthalpy change of neutralisation
The energy released when 1 mole of water is formed in the neutralisation reaction between an acid and a base, all in their
standard states, at a specified temperature, usually 298 K.
Define bond energy
Bond energy is the average energy required to break 1 mole of a covalent bond between two atoms in the gaseous state.
Define standard enthalpy change of atomisation of element
The energy required to form 1 mole of gaseous atoms from the element, all in their standard states, at a specified temperature, usually 298 K.
Define standard enthalpy change of atomisation of compound
The energy required to form gaseous atoms from the 1 mole of the compound, all in their standard states, at a specified temperature, usually 298 K.
Define lattice energy
The energy released when 1 mole of solid ionic compound is formed from its constituent gaseous ions.
Define first ionisation energy
The first ionisation energy is the energy required to remove 1 mole of electrons from 1 mole of gaseous atoms to form 1 mole of singly charged gaseous cations.
Define first electron affinity
The first electron affinity is the energy change when 1 mole of electrons is added to 1 mole of gaseous atoms to form 1 mole of singly charged gaseous anions.
Define standard enthalpy change of hydration
The energy released when 1 mole of free gaseous ions in its standard state is dissolved in water to give a solution of infinite dilution, at a specified temperature, usually 298 K.
Define standard enthalpy change of solution
The energy change when 1 mole of substance in its standard state is completely dissolved in a solvent to give a solution of
infinite dilution, at a specified temperature, usually 298 K.
Formula of heat change
q = - (mass)(heat change)(specific heat capacity)
q = - (heat capacity)(heat change)
Formula of heat change
q = - (mass)(heat change)(specific heat capacity)
q = - (heat capacity)(heat change)
Define standard state
The standard state of a substance at a specified temperature is its pure form at 1 bar (=10^5 Pa)*, and 1 mol dm^–3 for solutions.
