A change cannot occur spontaneously if it is accompanied by:
A. An energy decrease and an increase in randomness.
B. An energy increase and an increase in randomness.
C. An energy decrease and a decrease in randomness.
D. An energy increase and a decrease in randomness.
E. A Gibbs energy decrease.
D makes the most sense to me, but I don't know this stuff
I agree with you but I don't think much of the question.
What do you mean you don't think much of the question? That you think it is easy?
I didn't get it because does energy increase mean an exothermic or endothermic reaction because a reaction isn't spontaneous if the reaction is endothermic and the entropy decreases.
No, I thought the question was not a good question. My problem with it is I don't understand why each possible answer has anything about randomness(delta S). Perhaps I don't understand what the question means by more or less energy. I equated this with delta G (Gibbs free energy) until I read the D answer, then I didn't know what to think about energy. Perhaps energy is being used in the sense of delta H. So my response to you was a "wishy washy" I agree with your answer in that it makes some sense if we just knew for sure what more or less energy means.
The question asks which condition would prevent a change from occurring spontaneously when the change is accompanied by certain characteristics. In order to determine the correct answer, we need to understand the concept of spontaneity in relation to energy and randomness.
Spontaneous changes occur without any external influence, meaning they happen naturally. These changes are driven by the concepts of energy and entropy (which correlates to randomness or disorder). To predict the spontaneity of a change, we can use the Gibbs free energy equation:
ΔG = ΔH - TΔS
where ΔG is the change in Gibbs free energy, ΔH is the change in enthalpy (energy), ΔS is the change in entropy (randomness), and T is the temperature.
Now, let's break down the answer choices:
A. An energy decrease and an increase in randomness.
This condition facilitates a spontaneous change. The energy decrease (-ΔH) and increase in randomness (+ΔS) contribute to a negative ΔG value, making the change spontaneous.
B. An energy increase and an increase in randomness.
This condition will not promote a spontaneous change. The energy increase (+ΔH) would make ΔG positive, preventing the change from happening spontaneously, even with an increase in randomness.
C. An energy decrease and a decrease in randomness.
This condition will almost always facilitate a spontaneous change. The energy decrease (-ΔH) would result in a negative ΔG, promoting spontaneity. However, the decrease in randomness (-ΔS) could potentially counteract this effect in rare cases.
D. An energy increase and a decrease in randomness.
This condition will generally not promote a spontaneous change. The energy increase (+ΔH) will contribute to a positive ΔG, suggesting a non-spontaneous change. When accompanied by a decrease in randomness (-ΔS), it further discourages spontaneity.
E. A Gibbs energy decrease.
A decrease in Gibbs energy (ΔG) will facilitate spontaneous changes. However, this answer choice does not specify whether there are accompanying changes in energy or randomness.
Considering all options, we can conclude that the correct answer is D. An energy increase and a decrease in randomness would prevent a spontaneous change from occurring.