What can be said about an endothermic reaction with a negative entropy change? View Available Hint(s) The reaction is What can be said about an endothermic reaction with a negative entropy change? spontaneous at all temperatures. spontaneous at high temperatures. spontaneous at low temperatures. spontaneous in the reverse direction at all temperatures. nonspontaneous in either direction at all temperatures. Submit Part B What can be said about an exothermic reaction with a negative entropy change? View Available Hint(s) The reaction is What can be said about an exothermic reaction with a negative entropy change? spontaneous at all temperatures. spontaneous at high temperatures. spontaneous at low temperatures. spontaneous in the reverse direction at all temperatures. nonspontaneous in either direction at all temperatures.

The reaction is spontaneous at low temperatures

Explanation:

Let's first remember the definition of certain terms;

Enthalpy (H) in thermodynamics is defined as the heat content of a reaction. While Entropy (S) in thermodynamics is termed as the quantification of disorder or randomness of a reaction.

Gibb’s free energy change helps to determine the direction of the reaction.

Using the Gibbs free energy equation to solve this question.

∆G = ∆H - T∆S

Where;

∆G = Gibbs free energy

∆H = change in enthalpy

T= temperature of the reaction

∆S = change in entropy.

The question states that it is an exothermic reaction with negative entropy. This means that the change in both enthalpy and entropy will be negative. That is;

∆H = >0 ( it's positive)

∆S = < 0 (negative)

Let's remember that an exothermic reaction generally releases energy to it surroundings. This energy is usually released in the form of heat. Therefore, the change in enthalpy H of an exothermic reaction will always be negative. A negative change in entropy S indicates that there is a decrease in disorder, with respect to the reaction.

Using Gibb’s free energy equation at constant temperature and pressure, we have;

∆G = ∆H - T∆S

Now, the change in enthalpy and change in entropy can be written as follows;

∆H = >0 ( it's positive)

∆S = < 0 (negative)

Substitute these values in the above equation;

∆G = ∆H - T - (∆S)

∆G = ∆H + T∆S

According to the sign convention seen in the equation above,

Change in ∆G will be negative <0 when the value ∆H is greater than T∆S.

This change can occur only at low temperatures. Thus, this reaction is spontaneous at low temperatures.

1 is the answer to this problem