Thermodynamics

Question 1

Enthalpy change of formation

Answer 1

The enthalpy change when 1 mole of a compound is formed from its elements in their standard states under standard condition

Question 2

Enthalpy change of dissociation

Answer 2

The enthalpy change when 1 mole of bonds of the same type of molecule in the gaseous state is broken eg cl2 to 2cl

Question 3

electron affinity

Answer 3

The enthalpy change when one mole of 1- gaseous ions are made from 1 mole of gaseous atoms

Question 4

Lattice enthalpy of dissociation

Answer 4

The enthalpy change when 1 mole of a solid ionic compound is dissociated into gaseous ions under standard condition

Question 5

Lattice enthalpy of formation

Answer 5

The enthalpy change when 1 mole of solid ionic compound is formed from its gaseous ions under standard conditions

Question 6

Enthalpy change of 1st ionisation

Answer 6

The enthalpy change when 1 mole of gaseous 1+ ions are made from 1 mole of gaseous atoms

Question 7

Enthalpy change of 2nd ionisation

Answer 7

The enthalpy change when 1 mole of gaseous 2+ ions are made from 1 mole of gaseous atoms

Question 8

Enthalpy change of atomisation

Answer 8

The enthalpy change when 1 mole of gaseous atoms is made from an element is formed under its standard state

Question 9

enthalpy change of solution

Answer 9

The enthalpy change when 1 mole of an ionic substance is dissolved in the minimum amount of solvent to ensure no further enthalpy change is observed upon dilution

Question 10

Enthalpy of hydration

Answer 10

Enthalpy change when 1 mole of aqueous ions is made from 1 mole of gaseous ions

Question 11

Calculating enthalpy of solution

Question 12

Entropy (S) jk-1 mol-1

Answer 12

The measure of disorder in a system

Question 13

Entropy change (∆s)

Answer 13

Sproducts - Sreactans

Question 14

Entropically favourable

Answer 14

Is when the entropy change value is positive menaing it is entropically feasible

Question 15

Gibbs free energy ∆G

Answer 15

Tells us if a reaction is feasible or not

Question 16

Gibbs free energy equation

Answer 16

∆G= ∆H - T∆S

Question 17

T∆S

Answer 17

T= temperature in kelvins
∆S= entropy change (JK-1mol-1)

Question 18

∆H

Answer 18

Enthalpy change in j mol-1

Question 19

Gibbs free energy feasible reaction =

Answer 19

0 or negative