Enthalpy

Question 1

Give the definition of Lattice Enthalpy.

Answer 1

The enthalpy change when 1 mole of an ionic compound forms from its constituent gaseous ions under standard conditions (101kPa, 298K).

Question 2

Define the Standard Enthalpy Change of Atomisation.

Answer 2

The enthalpy change when 1 mole of gaseous atoms are formed from the element in its standard state under standard conditions.

Question 3

Define the First Electron Affinity.

Answer 3

The enthalpy change when 1 electron is added to each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1- ions.

Question 4

Define the Second Electron Affinity.

Answer 4

The enthalpy change when 1 electron is added to each ion in 1 mole of gaseous 1- ions to produce 1 mole of 2- gaseous ions.

Question 5

Define the Enthalpy Change of Solution.

Answer 5

The enthalpy change (energy absorbed or released) when 1 mole of an ionic solid dissolves in sufficient water to produce a very dilute solution.

Question 6

Define Enthalpy Change of Hydration.

Answer 6

The energy released when 1 mole of gaseous ions dissolve in sufficient water to produce a very dilute solution.

Question 7

Quote the formula that links Lattice, Solution and Hydration enthalpy changes.

Answer 7

Hyd= Latt + Sol

Question 8

Define Enthalpy Change of Neutralisation.

Answer 8

The enthalpy change when an acid and an alkali react to form 1 mole of water, under standard conditions.