Question

During a reaction, the enthalpy of formation of an intermediate is 90.3 kJ/mol. During the reaction, 2 moles of the intermediate are formed as a reactant. What is the enthalpy value for this step of the reaction?

A. -180.6 kJ

B. 90.3 kJ

C. -90.3 kJ

D. 180.6 kJ​

Answer 1

180.6 kJ​

Step-by-step explanation:

The enthalpy of reaction refers to the energy absorbed or released during a reaction. If heat is absorbed in a reaction, the enthalpy of reaction is positive. If heat is released in a reaction, the enthalpy of reaction his negative.

Since the energy absorbed when one mole of the intermediate is formed is 90.3 kJ/mol, then, when two moles of intermediate is formed, 2 × 90.3 kJ/mol = 180.6 kJ​ of energy is absorbed.