Which of the following processes is entropy increasing in the local system? You may select multiple processes.


Combination reactions where two reactants join to make a single product.

a system with increasing molecular motion

cooling a six-pack of beer by putting it in a cooler full of ice water (the beer is the system)

steam condensing

reactions that consume gaseous reactants and generate solid products

any spontaneous reaction in which delta-H is positive

Which do you think has more randomness? and why?

To determine which processes have an increasing entropy in the local system, let's first understand the concept of entropy.

Entropy is a measure of the randomness or disorder in a system. In simpler terms, it is the measure of how spread out or disorganized the particles or energy are within a system.

Now, let's analyze each given process:

1. Combination reactions where two reactants join to make a single product:
In this process, the reactants are typically more disordered than the product. As the reactants combine, their particles become more organized, resulting in a decrease in entropy.

2. A system with increasing molecular motion:
If the molecular motion within a system is increasing, it usually indicates that the particles are becoming more spread out and disordered. Therefore, the entropy is increasing.

3. Cooling a six-pack of beer by putting it in a cooler full of ice water (the beer is the system):
Cooling a system generally decreases the molecular motion and decreases the randomness of the particles. As a result, the entropy of the system decreases.

4. Steam condensing:
Steam condensing involves the transition from water vapor (gaseous state) to liquid water (liquid state). When a gas condenses into a liquid, the particles become more organized and confined, leading to a decrease in entropy.

5. Reactions that consume gaseous reactants and generate solid products:
The consumption of gaseous reactants and the formation of solid products often result in a decrease in molecular motion and a more ordered arrangement of particles, leading to a decrease in entropy.

6. Any spontaneous reaction in which delta-H is positive:
A spontaneous reaction is one that occurs naturally without requiring external intervention. If delta-H is positive in a spontaneous reaction, it suggests that the reaction favors an increase in randomness or disorder (i.e., increased entropy).

Based on the explanations above:

Processes where entropy is increasing in the local system include:
- A system with increasing molecular motion
- Any spontaneous reaction in which delta-H is positive

Processes where entropy is decreasing in the local system include:
- Combination reactions where two reactants join to make a single product
- Cooling a six-pack of beer
- Steam condensing
- Reactions that consume gaseous reactants and generate solid products