Question

Which statement is NOT correct?

A. You can increase entropy and still have a spontaneous reaction.

B. If there is a decrease in the energy of the system, the reaction is spontaneous.

C. Spontaneous reactions will tend to maximize entropy and minimize enthalpy at given temperature

D. Entropy can drive a reaction that is strongly endothermic

Answer 1

For a process that occurs at constant temperature and pressure, spontaneity can be determined using the change in Gibbs free energy, which is given by:

,

In cases where ΔG is:

• negative, the process is spontaneous and may proceed in the forward direction as written.

This set of rules can be used to determine four distinct cases by examining the signs of the ΔS and ΔH.

• When ΔS > 0 and ΔH < 0, the process is always spontaneous as written.
• When ΔS < 0 and ΔH > 0, the process is never spontaneous, but the reverse process is always spontaneous.
• When ΔS > 0 and ΔH > 0, the process will be spontaneous at high temperatures and non-spontaneous at low temperatures.
• When ΔS < 0 and ΔH < 0, the process will be spontaneous at low temperatures and non-spontaneous at high temperatures.

So as per this the only statement which is not true is

D. Entropy can drive a reaction that is strongly endothermic

because when a system is strongly endothermic meaning ΔH ha a large +ve value inclreaseing entropy will not make it positive.