Is the gas monatomic or diatomic?

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Homework Help Overview

The problem involves determining the molar heat capacities of an ideal gas when a specific amount of energy is supplied as heat at constant pressure, alongside a query about whether the gas is monatomic or diatomic.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the calculation of molar heat capacity at constant pressure and volume, with one participant attempting to derive values based on given equations. Questions arise regarding the relationship between Cp and Cv, and the meaning of specific terms in the equations.

Discussion Status

There is an ongoing exploration of the relationships between heat capacities and the ideal gas law, with participants offering guidance on how to approach the calculations. Multiple interpretations of the equations are being examined, and participants are questioning the definitions and implications of the variables involved.

Contextual Notes

Participants are working under the constraints of the problem statement, which specifies the energy supplied, the number of moles, and the temperature change, while also considering the nature of the gas in question.

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Homework Statement



130 J of energy is supplied as heat to 3.00 moles of an ideal gas at constant pressure, the temperature rises by 4.00 K.

Calculate the molar heat capacity at constant pressure, CP,m and the molar heat capacity at constant volume, CV,m for the gas.

Is the gas monatomic or diatomic?


Homework Equations



Cp= Q/ T

Cp= Cv + nR

Cp,m = Cv,m +R

The Attempt at a Solution



Cp= Q/ T
= 130/ 4= 32.5

Cp= Cv + nR
32.5 = Cv +3 (8.314)

Cv= 7.558

heat capacity at constant pressure Cp = 32.5
at capacity at constant volume Cv = 7.558

how do i go from here to calculate molar heat capacity..
 
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Divide Cp by the number of moles. Generally speaking, [tex]Cp=\frac{pdv}{ndt}+Cv[/tex] where Cp and Cv are molar heat capacities at constant pressure and volume.
 
Cp = nR + Cv

is nR= pdv/ ndt

what is dv/dt that u have in your formula...is the rate of change of volume...

or volume / temperautre?
 
Volume by temperature. You can use the ideal gas equation, PV=nRT, to find it under what ever conditions that are imposed on your system.
 

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