Entropy

Question 1

Feasible reaction delta H is? And why

Answer 1

More negative so more thermodynamicslly stable products so reaction is feasible

Question 2

Feasible reaction delta S is? And why

Answer 2

Positive as there is more disorder

Question 3

Feasible reaction delta G is? And why

Answer 3

Negative so reaction is more feasible

Question 4

Entropy increases with?

Answer 4

Increase in moles and from solid to gas

Question 5

Delta S system =

Answer 5

Products - Reactants

Question 6

Delta S surroundings =

Answer 6

• delta H/ T (H must be in Jmol -1)

Question 7

Delta S total =

Answer 7

System + surroundings

Question 8

Two equations for delta G (Gibbs Free Energy)

Answer 8

Delta G = delta H - Tdelta system

Delta G = -RTlnk

Question 9

A large delta G =

Answer 9

Large Kc

Question 10

Positive delta H and positive delta S:
What faces?
Tick/cross
Conditions?

Answer 10

Sad delta H
Happy delta S
At high temperatures feasible because TdeltaS outweighs the delta T hence delta G is negative

Question 11

Negative delta H and positive delta S:
What faces?
Tick/cross
Conditions?

Answer 11

Smiley and Smiley

Always feasible because delta G always negative

Question 12

Positive delta H and negative delta S:
What faces?
Tick/cross
Conditions?

Answer 12

Sad and Sad

Never feasible as delta G is always positive

Question 13

Negative delta H and Negative delta S:
What faces?
Tick/cross
Conditions?

Answer 13

Smiley delta H and sad delta S

At low temperatures then delta H outweighs -TdeltaS so delta G is negative

Question 14

When the activation energy is too high but products are more stable than reactants the reaction is called

Answer 14

Thermodynamically stable but kinetically inert

Question 15

When activation energy is met but reactants are more stable than products a reaction is called

Answer 15

Kinetically feasible but thermodynamically infeasible