are all isentropic processes adiabatic?
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So generally an adiabatic process is not necessarily isentropic -- only if the process is reversible and adiabatic we can call it isentropic. For example a real compressor can be assumed adiabatic but is operating with losses. Due to the losses the compression is irreversible. Thus the compression is not isentropic.
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All spontaneous processes are not exothermic, because it is the Gibbs Free energy that determines spontaneity, not the enthalpy. ... You will notice that this expression may be positive even with a negative enthalpy change (exothermic process) if the entropy change is negative and the temperature is high enough.
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For an exothermic reaction, the enthalpy change is always negative. In an endothermic reaction, the products are at a higher energy than the reactants. This means that the enthalpy change of the reaction (∆H) is positive.
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An isobaric process occurs at constant pressure. Since the pressure is constant, the force exerted is constant and the work done is given as PΔV. ... If a gas is to expand at a constant pressure, heat should be transferred into the system at a certain rate. This process is called an isobaric expansion.
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If a reaction is monitored with a thermometer and the temperature measured falls, did heat flow into the surroundings (qsurr is positive) or out of surroundings (qsurr is negative)? The heat energy lost by an exothermic reaction is characterized as a negative change of enthalpy of the reaction (ΔH°rxn ).
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Spontaneous processes occur without outside intervention. For example, a ball will roll down a hill with no external force required because of gravity. ... A spontaneous process is NOT determined by enthalpy. Nonspontaneous processes are not impossible.
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There are three types of systems in thermodynamics: open, closed, and isolated. An open system can exchange both energy and matter with its surroundings. ... A closed system, on the other hand, can exchange only energy with its surroundings, not matter.
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No properties change at the boundaries with time. Thus, the fluid properties at an inlet or exit will remain the same during the whole process. They can be different at different opens. The heat and work interactions between a steady-flow system and its surroundings do not change with time.
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Many processes work together to keep Earth's water moving in a cycle. There are five processes at work in the hydrologic cycle: condensation, precipitation, infiltration, runoff, and evapotranspiration.
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Yes. Every chemical reaction obeys the law of conservation of mass.
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In thermodynamics, a "process" is defined by a trajectory in thermodynamic state space from a starting point A to the end point B, and a "cycle" is just a closed trajectory going back to A. ... You might have reversible, or irreversible trajectories between two points.
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Fusion, vaporization, and sublimation are endothermic processes, whereas freezing, condensation, and deposition are exothermic processes. ... The conversion of a solid to a liquid is called fusion (or melting).
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Non-PV work can be, e.g. electrical work (think electrochemistry). From this, assuming that the process performed is reversible (in thermal equilibrium the whole way through), qrev=TdS , so: dG=qrevTdS +δwnon-PVwrev,PV−PdV +PdV +VdP−TdS −SdT.
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Polar jet stream At high latitudes, lack of friction allows air to respond freely to the steep pressure gradient with low pressure at high altitude over the pole. This results in the formation of planetary wind circulations that experience a strong Coriolis deflection and thus can be considered 'quasi-geostrophic'.
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The change in the internal energy of a system is the sum of the heat transferred and the work done. At constant pressure, heat flow (q) and internal energy (E) are related to the system's enthalpy (H). The heat flow is equal to the change in the internal energy of the system plus the PV work done.
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Some chemical systems become hotter as they react in an insulated container while others become colder, and a some show very little change in temperature. If the system becomes hotter as the written reaction occurs from left-to-right (the forward reaction), the reaction is said to be exothermic.
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The slower the reaction occurs, the greater the kinetic stability. If you say, "This reaction is kinetically stable," then that implies that the reaction occurs very slowly. Thermodynamic stability depends on whether or not the reaction is spontaneous. This depends on the change in free energy (ΔG).