Receiving Helpdesk

what is cp chemistry thermodynamics

by Dr. Baylee Funk DVM Published 3 years ago Updated 2 years ago

CV and CP are two terms used in thermodynamics. CV is the specific heat at constant volume, and CP is the specific heat at constant pressure. Specific heat is the heat energy required to raise the temperature of a substance (per unit mass) by one degree Celsius.Jul 26, 2017

Full Answer

What is the meaning of CP?

Cp: In a system, Cp is the amount of heat energy released or absorbed by a unit mass of the substance with the change in temperature at a constant pressure. In another words, under a constant pressure it is the heat energy transfer between a system and its surrounding.

What is the meaning of CP/CV in chemistry?

Cp/Cv is an indicator of how much gas in adiabatic conditions with dQ=0 can extract heat internally to do work. Cp/Cv is an indicator of how much gas in adiabatic conditions with dQ=0 can extract heat internally to do work.

What is chemical thermodynamics?

Chemical thermodynamics involves not only laboratory measurements of various thermodynamic properties, but also the application of mathematical methods to the study of chemical questions and the spontaneity of processes.

Who is the founder of chemical thermodynamics?

J. Willard Gibbs - founder of chemical thermodynamics. In 1865, the German physicist Rudolf Clausius, in his Mechanical Theory of Heat, suggested that the principles of thermochemistry, e.g. the heat evolved in combustion reactions, could be applied to the principles of thermodynamics.

What does CP mean in chemistry?

constant pressureCp is the term used to represent the molar heat capacity of a substance at constant pressure whereas, Cv is the term for molar heat capacity at constant volume. Thus, these two parameters define the molar heat capacity at varying pressure and temperature.

What is CP in heat transfer?

The specific heat capacity Cp [kJ/kg/°C] is a thermodynamic property specific of the fluid used to transfer heat. We could manipulate the specific heat capacity only by changing the fluid used in the loop.Oct 31, 2016

How do you find CP in thermodynamics?

1:459:09Relating Heat Capacities: Cp and Cv - YouTubeYouTubeStart of suggested clipEnd of suggested clipTimes the partial of n with respect to T at constant P. And you're in evaluate these two partialMoreTimes the partial of n with respect to T at constant P. And you're in evaluate these two partial derivatives multiply both of them by the temperature. And add that to CV. And that will give you CP.

What is CP & CV?

The Cp/Cv ratio is also called the heat capacity ratio. In thermodynamics, the heat capacity ratio is known as the adiabatic index. Cp/Cv ratio is defined as the ratio of two specific heat capacities. (i.e.) Heat Capacity ratio = Cp/Cv = Heat capacity at constant pressure/ Heat capacity at constant volume.

How do you calculate CP in chemistry?

The formula for specific heat capacity, C , of a substance with mass m , is C = Q /(m ⨉ ΔT) . Where Q is the energy added and ΔT is the change in temperature.Mar 26, 2022

What is CP for air?

The nominal values used for air at 300 K are CP = 1.00 kJ/kg. K, Cv = 0.718 kJ/kg.Jul 26, 2008

Is CP a constant?

So, Cp represents the molar heat capacity, C when pressure is constant. The change in temperature will always cause a change in the enthalpy of the system. Enthalpy (∆H) is the heat energy absorbed or released by the system.

Should I use CP or CV?

If you need Δu for a constant pressure process then Δu is still (Cv)ΔT. If you need to calculate a change in enthalpy, then you do it by using (Cp)ΔT -- no matter what the process is. If you need Δh for a constant volume process then Δh is still (Cp)ΔT.Apr 25, 2020

Why is CP is greater than CV?

At constant pressure, when a gas is heated, work is done to overcome the pressure and there is an expansion in the volume with an increase in the internal energy of the system. Therefore, it can be said that Cp is greater than Cv.

How do I find my CV and CP?

From the ideal gas law, P V = nRT, we get for constant pressure d(P V ) = P dV + V dP = P dV = nRdT . Substituting this in the previous equation gives Cp dT = CV dT + nRdT . Dividing dT out, we get CP = CV + nR . and CP = CV + nR = 5 2 nR .

What is the value of CP for water?

Water (liquid): CP = 4185.5 J⋅K−1⋅kg−1 (15 °C, 101.325 kPa) Water (liquid): CVH = 74.539 J⋅K−1⋅mol−1 (25 °C) For liquids and gases, it is important to know the pressure to which given heat capacity data refer.

What is the CP of water?

4.186 J/g°CWater has a specific heat capacity of 4.186 J/g°C, meaning that it requires 4.186 J of energy (1 calorie) to heat a gram by one degree.May 18, 2018

Summary

Chemical thermodynamics is the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the confines of the laws of thermodynamics. Chemical thermodynamics involves not only laboratory measurements of various thermodynamic properties, but also the application of mathematical methods to the study of chemical questions and the spontaneity of processes.

History

In 1865, the German physicist Rudolf Clausius, in his Mechanical Theory of Heat, suggested that the principles of thermochemistry, e.g. the heat evolved in combustion reactions, could be applied to the principles of thermodynamics. Building on the work of Clausius, between the years 1873-76 the American mathematical physicist Willard Gibbs published a series of three papers, the most famous one being the paper On the Equilibrium of Heterogeneous Substances. In these papers, …

Overview

The primary objective of chemical thermodynamics is the establishment of a criterion for determination of the feasibility or spontaneity of a given transformation. In this manner, chemical thermodynamics is typically used to predict the energy exchanges that occur in the following processes:
1. Chemical reactions

Chemical energy

Chemical energy is the energy released when chemical substances undergo a transformation through a chemical reaction. Breaking and re-making of chemical bonds involves energy release or uptake, often as heat that may be either absorbed or evolved from the chemical system.
Energy released (or absorbed) because of a reaction between chemical substances ("reactants") is equal to the difference between the energy content of the products and the reactants. This ch…

Chemical reactions

In most cases of interest in chemical thermodynamics there are internal degrees of freedom and processes, such as chemical reactions and phase transitions, which create entropy in the universe unless they are at equilibrium or are maintained at a "running equilibrium" through "quasi-static" changes by being coupled to constraining devices, such as pistons or electrodes, to deliver and receive external work. Even for homogeneous "bulk" systems, the free-energy functions depend …

Non-equilibrium

Generally the systems treated with the conventional chemical thermodynamics are either at equilibrium or near equilibrium. Ilya Prigogine developed the thermodynamic treatment of open systems that are far from equilibrium. In doing so he has discovered phenomena and structures of completely new and completely unexpected types. His generalized, nonlinear and irreversible thermodynamics has found surprising applications in a wide variety of fields.

See also

• Thermodynamic databases for pure substances

Further reading

• Herbert B. Callen (1960). Thermodynamics. Wiley & Sons. The clearest account of the logical foundations of the subject. ISBN 0-471-13035-4. Library of Congress Catalog No. 60-5597
• Ilya Prigogine & R. Defay, translated by D.H. Everett; Chapter IV (1954). Chemical Thermodynamics. Longmans, Green & Co. Exceptionally clear on the logical foundations as applied to chemistry; includes non-equilibrium thermodynamics.{{cite book}}: CS1 maint: multiple names: authors list (

Overview

This article is a summary of common equations and quantities in thermodynamics (see thermodynamic equations for more elaboration).

Definitions

Many of the definitions below are also used in the thermodynamics of chemical reactions.
Quantity (Common Name/s) (Common) Symbol/s SI Units Dimension Number of molecules N dimensionless dimensionless Number of moles n mol [N] Temperature T K [Θ] Heat Energy Q, q J [M][L] [T] Latent Heat QL J [M][L] [T]
Quantity (Common Name/s) (Common) Symbol/s Defining Equation SI Units Dimension Thermo…

Many of the definitions below are also used in the thermodynamics of chemical reactions.
Quantity (Common Name/s) (Common) Symbol/s SI Units Dimension Number of molecules N dimensionless dimensionless Number of moles n mol [N] Temperature T K [Θ] Heat Energy Q, q J [M][L] [T] Latent Heat QL J [M][L] [T]
Quantity (Common Name/s) (Common) Symbol/s Defining Equation SI Units Dimension Thermo…

Equations

The equations in this article are classified by subject.
Physical situation Equations Isentropic process (adiabatic and reversible) For an ideal gas Isothermal process For an ideal gas Isobaric process p1 = p2, p = constant Isochoric process V1 = V2, V = constant Free expansion Work done by an expanding gas Process Net Work Done in Cyclic Processes

Thermal properties of matter

Coefficients Equation Joule-Thomson coefficient Compressibility (constant temperature) Coefficient of thermal expansion (constant pressure) Heat capacity (constant pressure) Heat capacity (constant volume)
Derivation of heat capacity (constant pressure) Since
Derivation of heat capacity (constant volume) Since (where δWrev is the work done by the syste…

See also

• Antoine equation
• Bejan number
• Bowen ratio
• Bridgman's equations
• Clausius–Clapeyron relation

External links

• Thermodynamic equation calculator

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 1 2 3 4 5 6 7 8 9