Entropy of Mixing
### Formula:
$$\Delta S_{mix}=-nR\sum X_i\ln X_i$$
### Terminologies:
- ΔS_mix → Entropy change during mixing.
- n → Total number of moles.
- R → Gas constant.
- X_i → Mole fraction of component i.
- ln → Natural logarithm.
### Usage:
- Used to calculate entropy change when gases or solutions mix.