Topic 13: Further energetics

Question 1

the standard enthalpy change of atomisation of an element is

Answer 1

the enthalpy change measured at a stated temperature, usually 298K, and a pressure of 100kPa when one mole of gaseous atoms is formed from an element in its standard state

Question 2

the enthalpy change f solution, ΔsolH , is

Answer 2

the enthalpy change when one mole of an ionic solid dissolves in water to form an infinitely dilute solution

Question 3

the enthalpy change of hydration, ΔhydH , is

Answer 3

the enthalpy change when one mole of an ion in its gaseous state is completely hydrated by water

Question 4

entropy is

Answer 4

a property of matter that is associated with the degree of disorder, or degree of randomness, of the particles

Question 5

a spontaneous process is one that

Answer 5

takes place without continuous interventions from us

for this ΔStotal must be positive

Question 6

ΔStotal =

Answer 6

ΔSsystem + ΔSsurroundings

Question 7

ΔSsystem =

Answer 7

the sum of S(products) - the sum of S(reactants)

where ‘S’ is entropy

Question 8

ΔSsurroundings =

Answer 8

ΔH
- —-
T

of -ΔH/T

Question 9

ΔG =

ΔG also =

Answer 9

ΔG= -RTlnK
ΔG= ΔH - TΔSsystem