Understanding Bomb Calorimeters: Measuring ΔE and ΔH for Calorimetry Homework

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Bomb calorimeters measure the change in internal energy (ΔE) at constant volume, while coffee cup calorimeters measure the change in enthalpy (ΔH) at constant pressure. The relationship between ΔH and ΔE is expressed as ΔH = ΔE + PΔV, which indicates that work can be done in processes involving volume changes. In bomb calorimeters, since the volume is constant, ΔH equals ΔE, suggesting that no work is done and the energy change is solely from thermal energy transfer. The discussion highlights the importance of understanding the correct equations for accurate calorimetry homework. Clarifying these concepts is essential for proper application in thermodynamic calculations.
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Homework Statement


My book says that bomb calorimeters are used to measure ΔE while coffee cup calorimeters are used to measure ΔH. Isn't ΔE for bomb calirometers the same as ΔH?

Homework Equations

The Attempt at a Solution


Bomb Calorimeter:
ΔH = ΔE + PΔV = ΔE (since, constant volume).
So ΔH = ΔE.
So does that mean no work is done in bomb calorimeters and the change in energy is entirely due to the transfer of thermal energy?
 
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You have written wrong equation.
It is actually ΔH= ΔE + ΔPV
 
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