Question

Which of the following involve an increase in the entropy of the system? a. melting of a solid b. sublimation c. freezing d. mixing e. separation f. boiling

Short answer

The processes that involve an increase in entropy are melting of a solid (a), sublimation (b), mixing (d), and boiling (f).

Step-by-step solution

1. Melting of a solid

Melting of a solid involves a phase transition from a more ordered state (solid) to a less ordered state (liquid). In this process, the particles become more disordered, and the entropy of the system increases. So, melting of a solid involves an increase in entropy.

2. Sublimation

Sublimation is the phase transition from a solid directly to a gas without passing through the liquid phase. In this process, the particles become even more disordered than in the melting process, and the entropy of the system increases. So, sublimation involves an increase in entropy.

3. Freezing

Freezing is the phase transition from a liquid to a solid. This process involves a decrease in disorder since the particles become more ordered in a solid state. Therefore, freezing does not involve an increase in entropy.

4. Mixing

Mixing involves combining two or more substances. In this process, the particles of the different substances become more disordered due to the increased number of possible arrangements. Therefore, mixing results in an increase in entropy.

5. Separation

Separation is the process of dividing a mixture of substances into its components. This process involves a decrease in disorder since the different components become more ordered after separation. Therefore, separation does not involve an increase in entropy.

6. Boiling

Boiling is the phase transition from a liquid to a gas in which the liquid is heated to its boiling point. In this process, the particles become even more disordered than in the melting or sublimation processes due to the increased amount of space they can occupy. So, boiling involves an increase in entropy. In conclusion, the processes that involve an increase in entropy are melting of a solid (a), sublimation (b), mixing (d), and boiling (f).