-What is the change of state from liquid to solid at atmospheric pressure known as?
- AOption (a)
Solidification
- BOption (b)
Deposition
- COption (c)
Sublimation
- DOption (d)
Evaporation
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Correct answer
Solidification
Why this answer is correct
The correct answer is Solidification.
Key Points
- Solidification is the process by which a substance changes its state from a liquid to a solid. This typically occurs when the liquid is cooled to its freezing point.
- The freezing point is the temperature at which the liquid and solid phases of a substance coexist in equilibrium. For water, this temperature is 0°C (273.15 K) at standard atmospheric pressure.
- In the case of solidification, the molecules of the liquid lose kinetic energy due to cooling. As a result, they slow down and arrange themselves into a fixed, orderly structure, forming a solid.
- Solidification is an exothermic process, meaning it releases heat as the liquid transitions into a solid state.
- This process is a key principle in various natural phenomena and industrial applications, such as the formation of ice, the casting of metals, and the crystallization of substances.
Additional Information
- Deposition:
- Deposition is the direct change of state from gas to solid without passing through the liquid phase.
- An example of deposition is the formation of frost, where water vapor in the air turns directly into ice on cold surfaces.
- Sublimation:
- Sublimation refers to the change of state from a solid to a gas without passing through the liquid phase.
- An example of sublimation is the transformation of dry ice (solid carbon dioxide) directly into carbon dioxide gas.
- Evaporation:
- Evaporation is the process where a liquid changes to a gas at a temperature below its boiling point.
- It occurs at the surface of the liquid and is responsible for phenomena like drying of clothes and the cooling effect of sweat.
- Applications of Solidification:
- Metal casting: The process of shaping metals involves pouring molten metal into molds and allowing it to solidify.
- Ice formation: Solidification occurs naturally when water is cooled below its freezing point, forming ice.
- Crystallization: In industries, solidification is used to extract pure solid crystals from a solution.
Important Points
- Freezing vs. Solidification:
- Freezing is a specific type of solidification that occurs when a liquid turns into a solid at its freezing point.
- Solidification is a more general term that can apply to any liquid turning into a solid, regardless of the temperature or conditions.
- Latent Heat of Fusion:
- The latent heat of fusion is the amount of heat energy required to change a unit mass of a substance from solid to liquid (or vice versa) at constant temperature.
- For water, the latent heat of fusion is approximately 334 J/g.
- Phase Changes and Thermodynamics:
- All phase changes, including solidification, involve the transfer of energy in the form of heat.
- During solidification, the system releases heat to its surroundings, which is why it is classified as an exothermic process.