Thermodynamics

Question 1

Enthalpy of formation definition

Answer 1

Enthalpy change when one mole of a substance is for,ed from its elements under standard conditions
With all elements in standard states

Question 2

Enthalpy of combustion

Answer 2

When one mole of a substance is completely combusted in excess oxygen under standard conditions

Question 3

Bond dissociation Enthalpy

Answer 3

Enthalpy to break the bond in one mole of gaseous molecules
Form gas atoms
Cl2(g) —> 2Cl(g)

Question 4

Enthalpy of atomisation

Answer 4

Enthalpy change for the formation of one mole of gaseous atoms from elements in their standard state

Na(s) —> Na (g)

Question 5

First ionisation energy

Answer 5

Enthalpy change when one mole of electrons is removed from one mole of gaseous atoms to form one mole of +1 ions

Na(g) —> Na+(g) + e-

Question 6

first electron affinity

Answer 6

Entyalpy change when one mole of electrons is added to one mole of gaseous atoms