Answer:
b. Exothermic
Explanation:
Hello,
In this case, it is said that the enthalpy of the system decreases due to the chemical reaction, it means, that the products will have a less amount of enthalpy one the reaction is completed, such decrease will yield a negative change in the reaction enthalpy based on the shown below equation:
\(\Delta _RH=\Delta H_{products}-\Delta H_{reactants}\)
Thus, such phenomena accounts for the exothermic chemical reactions which have a change in the reaction enthalpy that is negative.
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