Question

You are given \(\Delta H\) for a process that occurs at constant pressure. What additional information do you need to determine \(\Delta E\) for the process?

Short answer

To determine the change in Internal energy (∆E) for a process that occurs at constant pressure, given the Enthalpy change (∆H), we need the following additional information: 1. The constant pressure (P) at which the process occurs. 2. The change in volume (∆V) during the process. This is because the relationship between ∆H and ∆E is given by the formula: \[ \Delta H = \Delta E + P\Delta V \]

Step-by-step solution

Understand the relationship between ∆H and ∆E

To find the additional information we need, we have to understand the relation between Enthalpy change (∆H) and Internal energy change (∆E) for a process that occurs at constant pressure. This relationship is given by the following formula: \[ \Delta H = \Delta E + P\Delta V \] Here, ∆H is the Enthalpy change, ∆E is the Internal energy change, P is the constant pressure, and ∆V is the change in volume.

Determine what additional information is needed

From the given relationship between ∆H and ∆E, we can see that in order to find ∆E, we need to know the pressure (P) and the change in volume (∆V) of the process in addition to ∆H. Since we already have ∆H, the additional information we need is: 1. The constant pressure (P) at which the process occurs. 2. The change in volume (∆V) during the process. So, to determine ∆E for a process that occurs at constant pressure, knowing the Enthalpy change (∆H), we need the constant pressure (P) and the change in volume (∆V) of the process as additional information.