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The molar heat capacity of an ideal gas ...

The molar heat capacity of an ideal gas in a process varies as `C=C_(V)+alphaT^(2)` (where `C_(V)` is mola heat capacity at constant volume and `alpha` is a constant). Then the equation of the process is

A

`Ve^(-((alphaT^(2))/(2R)))=` Constant

B

`Ve^(-((alphaT^(2))/(R)))=` constant

C

`Ve^(-((2alphaT^(2))/(R)))=` constant

D

`Ve^(-((3alphaT^(2))/(2R)))=` constant

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To solve the problem, we start with the given molar heat capacity of an ideal gas in a process: \[ C = C_V + \alpha T^2 \] where \( C_V \) is the molar heat capacity at constant volume, \( \alpha \) is a constant, and \( T \) is the temperature. ### Step 1: Use the First Law of Thermodynamics According to the first law of thermodynamics, we have: \[ dQ = dU + dW \] where: - \( dQ \) is the heat added to the system, - \( dU \) is the change in internal energy, - \( dW \) is the work done by the system. For an ideal gas, the change in internal energy can be expressed as: \[ dU = n C_V dT \] ### Step 2: Relate Heat Capacity to Heat Transfer From the definition of heat capacity, we can write: \[ dQ = n C dT = n (C_V + \alpha T^2) dT \] ### Step 3: Express Work Done The work done by the gas during an infinitesimal expansion can be expressed as: \[ dW = P dV \] Using the ideal gas law, we know that: \[ PV = nRT \] Thus, we can express pressure \( P \) as: \[ P = \frac{nRT}{V} \] Substituting this into the expression for work done gives: \[ dW = \frac{nRT}{V} dV \] ### Step 4: Substitute into the First Law Now substituting \( dU \) and \( dW \) into the first law gives: \[ n (C_V + \alpha T^2) dT = n C_V dT + \frac{nRT}{V} dV \] ### Step 5: Simplify the Equation Cancelling \( n C_V dT \) from both sides results in: \[ \alpha T^2 dT = \frac{RT}{V} dV \] ### Step 6: Rearranging the Equation Rearranging gives: \[ \frac{dV}{V} = \frac{\alpha}{R} T dT \] ### Step 7: Integrate Both Sides Now we integrate both sides: \[ \int \frac{dV}{V} = \int \frac{\alpha}{R} T dT \] The left side integrates to: \[ \ln V = \frac{\alpha}{R} \cdot \frac{T^2}{2} + \ln k \] where \( k \) is a constant of integration. ### Step 8: Exponentiate to Solve for V Exponentiating both sides gives: \[ V = k e^{\frac{\alpha T^2}{2R}} \] ### Step 9: Rearranging to Find the Final Form Rearranging this equation leads to: \[ V e^{-\frac{\alpha T^2}{2R}} = k \] This shows that the product \( V e^{-\frac{\alpha T^2}{2R}} \) is constant. ### Conclusion Thus, the equation of the process is: \[ V e^{-\frac{\alpha T^2}{2R}} = \text{constant} \]

To solve the problem, we start with the given molar heat capacity of an ideal gas in a process: \[ C = C_V + \alpha T^2 \] where \( C_V \) is the molar heat capacity at constant volume, \( \alpha \) is a constant, and \( T \) is the temperature. ### Step 1: Use the First Law of Thermodynamics According to the first law of thermodynamics, we have: ...
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