Understanding the Role of Entrainers and Solvents
When an entrainer or solvent is added to a mixture, it primarily affects the boiling point of one of the components. Here’s a detailed explanation of how this works:
Boiling Point Reduction
- Definition: The boiling point of a liquid is the temperature at which its vapor pressure equals the external pressure.
- Effect of Entrainer: Adding an entrainer or solvent alters the interactions between molecules in the mixture. This can lead to a reduction in the boiling point of one or more components due to:
- Lowering Vapor Pressure: The presence of the solvent can change the vapor pressure of the component, effectively making it easier for the component to vaporize.
- Azeotropic Behavior: In some cases, the addition of an entrainer can create an azeotrope, which is a mixture that has a constant boiling point and composition. This can also lead to a lower boiling point compared to the pure component.
Impact on Other Points
- Bubble Point: The bubble point is the temperature at which the first bubble of vapor forms in a liquid mixture. While this can be affected, the primary focus of using an entrainer is on the boiling point.
- Dew Point: The dew point is the temperature at which vapor begins to condense. Similar to the bubble point, its relationship with the entrainer is secondary to that of boiling point.
Conclusion
In summary, when an entrainer or solvent is introduced to a mixture, the most significant change observed is the reduction in the boiling point of one of the components, making option 'A' the correct answer. This principle is widely utilized in processes such as distillation to improve separation efficiency.