Chapter 22 definitions

Question 1

Standard enthalpy change of formation.

Answer 1

The enthalpy change when one mole of a compound is formed from its constituent elements in their standard states under standard conditions.

Question 2

First ionisation energy.

Answer 2

The enthalpy change when one electron is removed from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions.

Question 3

ΔrH⊖

Answer 3

An enthalpy change that accompanies a reaction in its molar quantities shown in a chemical equation under standard conditions, with all reactants and products in their standard states.

Question 4

Standard enthalpy change of hydration.

Answer 4

The enthalpy change that occurs when one mole of isolated gaseous ions is dissolved in water forming one mole of aqueous ions under standard conditions.

Question 5

ΔfH⊖

Answer 5

The enthalpy change that takes place when one mole of a compound is formed from its elements under standard conditions, with all reactants and products in their standard states.

Question 6

ΔcH⊖

Answer 6

The enthalpy change that takes place when one mole of a substance reacts completely with oxygen under standard conditions, with all reactants and products in their standard states.