Q: How is boiling different from sublimation?
In boiling the molecules pass from the liquid state to the vapor state.
In sublimation, the molecules pass DIRECTLY from the solid state to the vapor state without going through the liquid state.
Boiling and sublimation are both physical processes that involve changing the state of matter. However, there are some key differences between them:
1. Definition:
- Boiling: Boiling is the process in which a liquid turns into a gas at its boiling point by the addition of heat.
- Sublimation: Sublimation is the process in which a solid directly transitions into a gas without passing through the liquid state when heated.
2. Temperature:
- Boiling: Boiling occurs at a specific temperature called the boiling point, which is unique for each substance. The boiling point of a substance remains constant throughout the process until all the liquid has been converted into a gas.
- Sublimation: Sublimation occurs at temperatures below the substance's melting point, but above its freezing point. The substance directly transitions from solid to gas without entering the liquid state.
3. Process:
- Boiling: During boiling, energy is added to the liquid, which increases the kinetic energy of its particles. As the particles gain energy, they overcome the intermolecular forces holding them together, and the liquid turns into a gas.
- Sublimation: During sublimation, energy is also added to the solid, causing its particles to gain enough energy to break the intermolecular forces holding them in their fixed positions. The solid then transitions directly into a gas without first becoming a liquid.
4. Examples:
- Boiling: Boiling commonly occurs when water is heated, turning it into steam.
- Sublimation: An example of sublimation is the process of dry ice (solid carbon dioxide) turning into carbon dioxide gas when exposed to room temperature.
In summary, boiling involves the transition from liquid to gas at the boiling point, while sublimation involves the direct transition from solid to gas without passing through the liquid phase.
Boiling and sublimation are both processes of transitioning matter from one state to another, but they occur under different conditions and involve different changes.
Boiling is the process where a liquid changes into a gas by the formation of bubbles within the liquid. It generally occurs when a liquid is heated to its boiling point, which is the temperature at which its vapor pressure equals the atmospheric pressure. At this point, the liquid molecules have enough energy to overcome intermolecular forces and break free from their liquid arrangement, resulting in the conversion into gas. Boiling typically occurs at a specific temperature for each substance.
Sublimation, on the other hand, is the direct transition of a substance from a solid to a gas without going through the liquid phase. This happens when a solid substance, under specific temperature and pressure conditions, gains enough energy to overcome the intermolecular forces holding its particles together. Instead of melting into a liquid, the substance directly transforms into a gas. An example is dry ice (solid carbon dioxide), which can undergo sublimation at normal atmospheric pressure and temperature, turning directly from a solid into a gas without first becoming a liquid.
To determine the specific differences between boiling and sublimation for a particular substance, you can refer to its phase diagram. A phase diagram shows the relationship between temperature and pressure at which a substance exists in different states (solid, liquid, gas), as well as the conditions at which phase transitions occur.
In summary, boiling involves the conversion of a liquid into a gas by heating it to its boiling point, while sublimation refers to the direct transition of a solid into a gas without first becoming a liquid. The conditions and temperature required for each process differ, and examining the phase diagram of a substance can provide more specific information.