It doesn't change the enthalpy of the reaction. It does change the activation enthalpy of the reaction.brake4country said:However, how does this change the enthalpy?
Enthalpy is a thermodynamic property that measures the total energy of a system. Activation energy is the minimum energy required for a chemical reaction to occur. Enthalpy and activation energy are related because they both involve the energy changes that occur during a chemical reaction.
The change in enthalpy during a reaction can affect the rate at which the reaction occurs. If the enthalpy change is negative (exothermic), the reaction will release energy and proceed at a faster rate. If the enthalpy change is positive (endothermic), the reaction will absorb energy and proceed at a slower rate.
Enthalpy and activation energy cannot be measured directly, but they can be calculated using thermodynamic equations and experimental data. Enthalpy can be measured indirectly through calorimetry, while activation energy can be determined through kinetics experiments.
Exothermic reactions have a negative enthalpy change, meaning that they release energy. This also means that their activation energy is lower, as less energy is needed to start the reaction. Endothermic reactions have a positive enthalpy change, meaning that they absorb energy. Their activation energy is higher, as more energy is needed to overcome the energy barrier and initiate the reaction.
The change in enthalpy and activation energy can be used to calculate the Gibbs free energy of a reaction, which is a measure of the spontaneity of a reaction. If the Gibbs free energy is negative, the reaction is spontaneous and will proceed in the forward direction. If the Gibbs free energy is positive, the reaction is non-spontaneous and will not occur without the input of energy.