Mo(CO)5 is the intermediate in this reaction mechanism.
Explanation:
The reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products. Reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism.
In this reaction mechanism, Mo(CO)5 is the product of 1st reaction and then it is used as a reactant in 2nd reaction. So, Mo(CO)5 is the reaction intermediates.
Exothermic reactions is where energy is released. Exothermic reactions are reactions that release energy into the environment in the form of heat. Exothermic reactions feel warm or hot or may even be explosive.