Thermodynamics 5

Question 1

enthalpy of a solution.

Answer 1

enthalpy of a solution of a substance is the enthalpy change when one mole of it resolves in a specified amount of solid.

Question 2

enthalpy or solution at infinite dilution

Answer 2

it is the enthalpy observed on dissolving the substance in an infinite amount of solvent when the interaction between the ions are negligible.

Eg: -
KCl (s) + H2O –> KCl (aq)
delta sol H = 18.6 kJ/mol

Question 3

Lattice enthalpy

Answer 3

Lattice enthalpy of an ionic compound is the enthalpy change which occurs when 1 mole of an ionic compound dissociates into its ions into gaseous states.

Question 4

Spontaneous process

Answer 4

A process which under some given conditions may take place by itself or initiation, independent of the rate.
Eg: - Dissolution of the sugar, evaporation in an open vessel.
2H2 + O2 –> 2H2O

Question 5

Non - spontaneous process.

Answer 5

The process which do not take place on its own.
Eg: - dissolution of sand.

Question 6

Define Entropy

Answer 6

Entropy is the measure of randomness or disorder in the system..
- it sis also a state function.
- Greater the dissorderness, greater the entropy.

Question 7

delta S sign

Answer 7

• For a system in eqbm, delts S = 0
• For a spontaneous process, delta S = +ve
• For a non- spontaneous process, delta S = -ve.