Final answer:
In considering entropy changes for different processes, the phase change, dispersion of particles, temperature change, and chemical reaction molecule counts all influence entropy. Smoke spreading out and water boiling both increase entropy, whereas the formation of NH3 from H2 and N2 decreases entropy. Therefore, all given processes (A, B, C) affect entropy, with A and B increasing it, and C decreasing it.
Step-by-step explanation:
Entropy is a measure of disorder or randomness in a system. When analyzing whether a process will result in an increase or decrease in entropy, several factors must be considered:
- The phase changes of substances; for example, a phase change from solid to liquid or liquid to gas generally results in an increase in entropy.
- The dispersal of particles; when a substance breaks into smaller parts, its entropy increases.
- Temperature changes; an increase in temperature often leads to an increase in entropy as particles move more rapidly.
- The number and type of molecules involved in a chemical reaction. Generally, an increase in the number of product molecules compared to reactant molecules will result in increased entropy, especially if gases are involved.
Applying these principles to the given options:
- (A) Smoke from a cigarette disperses throughout a room would increase entropy, as the smoke particles spread out and increase disorder.
- (B) Water boils, changing from liquid to vapor, would also increase entropy due to the phase change from liquid to gas.
- (C) The chemical reaction 3 H2 (g) + N2 (g) → 2 NH3 (g) would result in a decrease in entropy because there is a reduction in the total number of gas molecules from 4 to 2.
Thus, the correct answer is (D) All of the above, as processes A and B lead to an increase in entropy, while process C leads to a decrease in entropy.