To calculate the change in thermal energy of a chemical reaction, you need to consider two main factors: the change in heat and the work done during the reaction.
1. Change in Heat (ΔQ): This represents the amount of heat energy that is either absorbed or released during the chemical reaction. It can be measured or calculated using calorimetry or other thermodynamic data.
2. Work Done (W): This is the energy associated with the work done by the system, such as the expansion or compression of gases. In many cases, this is related to changes in volume and pressure of the reacting system.
The change in thermal energy (ΔE) in a system can be expressed as the sum of these two components. So, the correct expression for calculating the change in thermal energy is:
[tex]\[ \Delta E = \Delta Q + W \][/tex]
where:
- [tex]\( \Delta E \)[/tex] is the change in thermal energy,
- [tex]\( \Delta Q \)[/tex] is the change in heat,
- [tex]\( W \)[/tex] is the work done by or on the system.
Therefore, the correct answer to how the change in thermal energy is calculated is:
The change in thermal energy is equal to the change in heat plus the work done.
