5.2.2 Enthalpy and Entropy

Question 1

explain that entropy is a measure of the‘disorder’ of a system, and that a system becomes energetically more stable when it becomes more disordered;

Question 2

explain the difference in magnitude of

entropy:

(i) of a solid and a gas,
(ii) when a solid lattice dissolves,
(iii) for a reaction in which there is a change in the number of gaseous molecules;

Question 3

calculate the entropy change for a reaction

given the entropies of the reactants and

products;

Question 4

explain that the tendency of a process to take place depends on temperature, T, the entropy change in the system, S, and the enthalpy change, H, with the surroundings

Question 5

explain that the balance between entropy and

enthalpy changes is the free energy change,

G, which determines the feasibility of a

reaction;

Question 6

state and use the relationship

*delta *G = delta H – T delta S;

Question 7

explain, in terms of enthalpy and entropy,

how endothermic reactions are able to take

place spontaneously