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The relation of internal energy, enthalp...

The relation of internal energy, enthalpy and work done can be represented by:

A

`DeltaE= DeltaH+W`

B

`DeltaE = W- DeltaH`

C

`DeltaH= DeltaE+W`

D

`W= DeltaE- DeltaH`

Text Solution

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The correct Answer is:
To derive the relationship between internal energy (ΔU), enthalpy (ΔH), and work done (W), we can follow these steps: ### Step-by-Step Solution: 1. **Understanding Enthalpy**: Enthalpy (H) is defined as the sum of the internal energy (U) of a system and the product of its pressure (P) and volume (V): \[ H = U + PV \] 2. **Change in Enthalpy**: The change in enthalpy (ΔH) can be expressed as: \[ \Delta H = \Delta U + P\Delta V \] Here, ΔU is the change in internal energy, and PΔV is the work done when the pressure is constant. 3. **First Law of Thermodynamics**: According to the first law of thermodynamics, the change in internal energy (ΔU) is given by: \[ \Delta U = Q + W \] where Q is the heat added to the system and W is the work done by the system. 4. **Substituting Work Done**: In a constant pressure process, the work done (W) can be expressed as: \[ W = -P\Delta V \] Substituting this into the equation for ΔU gives: \[ \Delta U = Q - P\Delta V \] 5. **Combining Equations**: Now, we can substitute ΔU from the first law into the equation for ΔH: \[ \Delta H = (Q - P\Delta V) + P\Delta V \] Simplifying this, we find: \[ \Delta H = Q \] when the pressure is constant. 6. **Final Relationship**: Rearranging the equation for ΔH gives us the relationship between ΔU, ΔH, and W: \[ \Delta U = \Delta H - P\Delta V \] Since \(W = -P\Delta V\), we can express this as: \[ \Delta U = \Delta H + W \] ### Final Result: Thus, the relationship between internal energy, enthalpy, and work done can be summarized as: \[ \Delta U = \Delta H + W \]

To derive the relationship between internal energy (ΔU), enthalpy (ΔH), and work done (W), we can follow these steps: ### Step-by-Step Solution: 1. **Understanding Enthalpy**: Enthalpy (H) is defined as the sum of the internal energy (U) of a system and the product of its pressure (P) and volume (V): \[ H = U + PV ...
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