Question

The standard reaction enthalpy may be estimated by combining enthalpies of formation"

A) True
B) False
C) Only in closed systems
D) Depends on temperature

Answer 1

True, the standard reaction enthalpy can be estimated by combining the enthalpies of formation of reactants and products, in accordance with Hess's Law.

Step-by-step explanation:

The standard reaction enthalpy can indeed be estimated by combining enthalpies of formation. This method is based on Hess's Law, which allows for the calculation of enthalpy changes for a given reaction by knowing the enthalpy changes for the formation of the reactants and products. The standard reaction enthalpy is calculated by taking the sum of the standard enthalpies of formation of the products and subtracting the sum of the standard enthalpies of formation of the reactants. This is independent of the reaction path and is true regardless of whether the system is closed or not and is generally considered at a reference temperature of 25°C and a pressure of 1 atmosphere.