Question

How can a reaction with a negative value of ▲ Gº be described?OA. As exothermicOB. As spontaneousOC. As endothermicOD. As nonspontaneous

Answer 1

Exothermic is the best choice.

Step-by-step explanation:

A negative sign for ΔG means that energy was released from the system. The term for that is exothermic (exo means outside). Endothermic reaactions absorb energy from their surroundings. [They are no fun.] Spontaneous reactions can be endothermic or exothermic. Most will be exothermic, so it is tempting to select this as the answer. But all exothermic reaction have a negative ΔG, so it is the best choice.

Answer 2

Answer: A negative value of ΔG describes a spontaneous reaction (letter B).

Step-by-step explanation:

The question requires us to choose the correct option that describes a reaction with negative value of free energy change (ΔG).

Free energy (G) refers to the energy that is available to a system to do work. It refers to the spontainety of a chemical reaction rather than the heat energy that is released or absorbed by the system as the reaction occurs.

As the spontainety of a reaction is determined by the enthalpy and entropy changes (ΔH and ΔS, respectively) that occur in the system, free energy change (ΔG) can be defined in terms of ΔH and ΔS:

`ΔG^°=ΔH^°-TΔS^°`

A spontaneous chemical reaction is one that releases energy, thus the reaction will be spontaneous when ΔG value is negative.