Thermodynamics

Question 1

hat is enthalpy change?

Answer 1

Heat change at a constant pressure.

Question 2

What is lattice enthalpy enthalpy of formation?

Answer 2

The enthalpy change when 1 mole of a solid ionic compound is formed from its gaseous ions.

Question 3

What is lattice dissociation enthalpy?

Answer 3

The enthalpy change when 1 mole of a solid compound is completely dissociated into its gaseous ions.

Question 4

What is enthalpy change of formation?

Answer 4

The enthalpy change when 1 mole of a compound is formed from its constituent elements under standard conditions and standard states.(Exo)

Question 5

What is enthalpy of combustion?

Answer 5

Enthalpy change when 1 mole of a compound undergoes complete combustion in oxygen under standard conditions and standard states.(Exo)

Question 6

What is enthalpy of neutralisation?

Answer 6

Enthalpy change when 1 mole of water is formed in a reaction between an acid and alkali under standard conditions and standard states.(Exo)

Question 7

What is ionisation enthalpy for first ionisation energy?

Answer 7

Enthalpy change when each atom in 1 mole of gaseous atoms loses 1 electron to form 1 mole of gaseous 1+ ions.(Endo)

Question 8

What is ionisation enthalpy for second ionisation energy?

Answer 8

Enthalpy change when each ion in 1 mole of gaseous 1+ ion loses 1 electron to form 1 mole of gaseous 2+ ions.(Endo)

Question 9

What is first electron affinity?

Answer 9

Enthalpy change when each atom in 1 mole of gaseous atoms gains 1 electron to form 1 mole of gaseous 1- ions.(Exo)

Question 10

What is second electron affinity?

Answer 10

Enthalpy change when each ion in 1 mole of gaseous 1- ions gains 1 electron to form 1 mole of gaseous 2- ions.(Endo)

Question 11

What is enthalpy of atomisation?

Answer 11

Enthalpy change when 1 mole of gaseous atoms is produced from an element in its standard states.(Endo)

Question 12

What is hydration enthalpy?

Answer 12

Enthalpy change when 1 mole of gaseous ions become hydrated(dissolved in water).(Exo)

Question 13

What is enthalpy of solution?

Answer 13

Enthalpy change when 1 mole of an ionic solid is dissolved in an amount of water large enough so that the dissolved ions are well separated and do not interact with each other.

Question 14

What is bond dissociation enthalpy?

Answer 14

Enthalpy change when 1 mole of covalent bonds are broken in the gaseous state.(Endo)

Question 15

What is enthalpy of vaporisation?

Answer 15

Enthalpy change when 1 mole of a liquid is turned into a gas.(Endo).

Question 16

What is entropy?

Answer 16

A measure of disorder-number of ways that particles can be arranged and the number of ways the energy can be shared out between particles.

Question 17

What affects entropy?

Answer 17

Physical state
Dissolution
Number of particles

Question 18

What is the formula for entropy change.

Answer 18

Entropy Change= Entropy of Products-Entropy of reactants.

Question 19

What is Gibbs Free Energy Change.

Answer 19

A measure used to predict whether a reaction is feesible.

Question 20

What is the formula for free energy change.

Answer 20

= Enthalpy Change - Temperature x Entropy Change.