Free energy change (ΔG) .... state function

Question

The free energy change (ΔG) is a state function, which means all of

the following except:

The choices are:

1. The energy change for the reaction A to B depends only on the

initial and final states, and is independent of the path taken from A to B.

2. The overall energy change for the reaction A to B could be

calculated by summing the energy changes for a series of separate reactions that could convert A to B.

3. The rate of the reaction can be determined from the energy change.

The answer is:

a) 1

b) 2

c) 3

d) Both 1 and 2

e) All of these

is it d?

Answer 1

The correct answer is D.  

Neither C nor E are correct because the statement number 3 is incorrect.  The rate of the reaction critically depends on the pathway the reaction takes.  While a reaction may have a net negative change in the Gibbs free energy (G) indicating that it is thermodynamically favorable, the reaction might have to go through pathways that require moving over energy barriers.  These barriers control the rate of the reaction.