Reversible Phase Change
Reversible Phase Change - Related Videos
01:10
Entropy Change in Reversible Processes
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2023
In the Carnot engine, which achieves the maximum efficiency between two reservoirs of fixed temperatures, the total change in entropy is zero. The observation can be generalized by considering any reversible cyclic process consisting of many Carnot cycles. Thus, it can be stated that the total entropy change of any ideal reversible cycle is zero. The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.
07:59
Synthesis and Characterization of Multi-Modal Phase-Change Porphyrin Droplets
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Cited by 1 •
2021
In this protocol, methods for synthesizing and characterizing multi-modal phase-change porphyrin droplets are outlined.
03:31
Reversed-Phase High-Performance Liquid Chromatography: A Robust Method for Quantitation of Fluorescently Labeled and Derivatized Sialic Acids Isolated from Mouse Liver
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2025
In this video, we demonstrate the detection of sialic acids, N-acetylneuraminic acid and N-glycolylneuraminic acid, using high-performance liquid chromatography, HPLC, following derivatization with a suitable fluorescent labeling reagent to aid in fluorescence detection.
12:22
The Use of Reverse Phase Protein Arrays (RPPA) to Explore Protein Expression Variation within Individual Renal Cell Cancers
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Cited by 12 •
2013
RPPA enables the protein expression of hundreds of samples, printed on nitrocellulose slides to be interrogated simultaneously, using fluorescently labelled antibodies. This technique has been applied to study the effect of drug treatment heterogeneity within clear cell renal carcinoma.
02:33
Phase Transitions: Sublimation and Deposition
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2020
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
FAQs
Heating supplies energy that allows particles to overcome intermolecular attractions, promoting transitions such as melting or vaporization. Cooling removes energy, allowing attractions to form again during freezing or condensation. This particle-level balance explains why a substance can move between physical states while retaining its chemical identity, which is central to interpreting phase behavior in chemistry.
Temperature changes the energy available to particles, while pressure changes the conditions under which different states are favored. Together, these variables define the conditions for melting, freezing, vaporization, condensation, sublimation, and deposition. Chemists use their relationship to interpret phase diagrams and identify the conditions under which a substance changes state.
Latent heat provides a way to measure the energy change associated with a phase transition. Rather than focusing only on the substance’s state, this quantity connects the observed transformation with the energy absorbed or released as intermolecular attractions are overcome or formed. Its measurement supports thermal analysis and helps characterize how materials respond to heating and cooling.
Melting changes a solid to a liquid, while vaporization changes a liquid to a gas. Sublimation moves directly from solid to gas. The reverse processes are freezing, condensation, and deposition, respectively. Grouping transitions by their direction clarifies whether heating or cooling promotes the change and helps organize the pathways represented in chemical phase diagrams.
A phase diagram relates the states of a substance to temperature and pressure, allowing chemists to identify regions where a particular phase is present and conditions where transitions occur. By examining movement across the diagram, researchers can connect changes in experimental conditions with melting, vaporization, sublimation, or their reverse processes during material characterization.
Phase transitions can absorb or release measurable energy, making them relevant to systems designed to manage thermal energy. Thermal energy storage uses this energy exchange to retain or deliver heat, while refrigeration relies on controlled changes between states. Understanding the associated conditions and latent heat helps chemists interpret how these systems transfer energy during operation.
Distillation depends on controlled vaporization and condensation to manage material separation, so understanding the conditions governing these transitions is essential. In chemical research, reversible phase change also supports material characterization by linking observed physical transformations with temperature, pressure, and energy changes. These connections help researchers interpret experimental behavior without implying a change in chemical identity.