confusion on using Cp and Cv
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confusion on using Cp and Cv
Do we use Cp when we are told the pressure is constant or when we are told the volume is constant? I know it means "constant pressure", but if anyone has an example of a question that directly points to us using Cp versus Cv could you please respond with it?
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Re: confusion on using Cp and Cv
We use Cp when told that the pressure is constant and Cv when told that the volume is constant. The C part is referring to the heat capacity, and the p and v are referring to what is being held constant. Hope this clears up some confusion. Problem 4.C.3 in the textbook uses both Cp and Cv, so you might want to check it out.
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Re: confusion on using Cp and Cv
To add onto the relationship between Cp and Cv, Cp = Cv + R so the other can be found when given one. The usage of either Cp and Cv will depend on which is constant like people mentioned above.
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Re: confusion on using Cp and Cv
What I like to do is I use the one that is mentioned in the problem. If the question is focusing on volume I use Cp and when it is focusing on pressure I use Cp. Although we may be given the initial and final volumes/pressures in the question, when we calculate using the Cv of Cp, we assume the volume/pressure change already occurred and that they are constant.
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Re: confusion on using Cp and Cv
Cp = Heat capacity at constant pressure
Cv = Heat capacity at constant volume
The problem will most likely give you one of these values
Cv = Heat capacity at constant volume
The problem will most likely give you one of these values
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Re: confusion on using Cp and Cv
Cp is the heat capacity at constant pressure, and Cv is the heat capacity at constant volume. They are related by the equation Cp = Cv + R.
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Re: confusion on using Cp and Cv
Cp is the heat capacity at constant pressure while Cv is the heat capacity at constant volume.
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Re: confusion on using Cp and Cv
Hi,
Yes! Recall, C refers to the heat capacity, or the amount of heat to raise the temperature of a substance by 1 unit of temperature. The subscript "P" or "V" is indicative of what variable we are assuming is constant.
If it is "C_p," then it is the heat capacity at constant pressure. If it is "C_v," then it is the heat capacity at constant volume.
Hope this helps! :)
Yes! Recall, C refers to the heat capacity, or the amount of heat to raise the temperature of a substance by 1 unit of temperature. The subscript "P" or "V" is indicative of what variable we are assuming is constant.
If it is "C_p," then it is the heat capacity at constant pressure. If it is "C_v," then it is the heat capacity at constant volume.
Hope this helps! :)
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Re: confusion on using Cp and Cv
Hi, Cp is when pressure is constant and Cv is when volume is constant. You can tell by looking at the subscript next to the "C". Hope this helps!
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Re: confusion on using Cp and Cv
Cp is used with constant pressure and Cv is used with constant volume.
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Re: confusion on using Cp and Cv
Cp is the heat capacity value for constant pressure and Cv is the heat capacity value for constant volume. We will typically use these values when the problem explicitly states when the system is under conditions of constant pressure or value, but keep an eye out if ideal gas conditions are also described.
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Re: confusion on using Cp and Cv
Cp is used when it is mentioned that there is constant pressure, and Cv is used when it is mentioned that there is constant volume!
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Re: confusion on using Cp and Cv
Cp is used under conditions of constant pressure and Cv is used under conditions of constant volume.
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Re: confusion on using Cp and Cv
We use Cp when pressure is constant and Cv when volume is constant. Remember the difference between diatomic and monatomic
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Re: confusion on using Cp and Cv
Cp is used for conditions of constant pressure, and Cv is used for conditions of constant volume.
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Re: confusion on using Cp and Cv
Cp is used for conditions of constant pressure, and Cv is used for conditions of constant volume.
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Re: confusion on using Cp and Cv
Usually you find theneed to use Cp or Cv when looking at changes in entropy when temperature varies. When temperature varies, the problem usually keeps either pressure or volume constant. If pressure is constant, then Cp is used. If volume is constant, then Cv is used.
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Re: confusion on using Cp and Cv
Cp is the heat capacity when pressure is constant and Cv is the heat capacity when volume is constant. They are used in the equation Cp=Cv+R.
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Re: confusion on using Cp and Cv
Cp is for conditions with constant pressure, and Cv is for conditions with constant volume
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Re: confusion on using Cp and Cv
Cp is for when the pressure is constant and Cv is for when the volume is constant. They're usually given and if the question mentions that the gas is ideal, then the values can be found on the formula sheet
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Re: confusion on using Cp and Cv
Cp is the heat capacity at constant pressure while Cv is the heat capacity at constant volume.
Also, Cp = Cv + R
Also, Cp = Cv + R
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Re: confusion on using Cp and Cv
Cp=Cv + R. Cp refers to the conditions under constant pressure, Cv refers to constant volume. If you take a look at the textbook problems you’ll find abundant examples
Re: confusion on using Cp and Cv
Cp is heat capacity at a constant pressure while Cv is heat capacity at constant volume.
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