Final Answer:
The energy given off when g is reacted with excess is A) Exothermic.
Step-by-step explanation:
When a substance reacts with excess, it means that one of the reactants is present in an amount greater than required for the reaction to complete. In an exothermic reaction, the products have lower energy than the reactants, resulting in the release of energy to the surroundings. The excess reactant does not affect the energy outcome, and the reaction overall is characterized by the liberation of heat. Therefore, the correct choice is A) Exothermic.
Exothermic reactions typically involve breaking and forming bonds. The released energy appears in the form of heat, light, or sound. In contrast, endothermic reactions absorb energy from the surroundings, causing a decrease in temperature. The term ""excess"" in this context implies that the limiting reactant is completely consumed, and any additional reactant will not alter the energy outcome. This distinction is essential in understanding the thermodynamics of a chemical reaction and predicting whether it absorbs or releases energy.
In summary, the reaction of g with excess is classified as exothermic, indicating that the overall process releases energy. This is a fundamental concept in chemistry, crucial for understanding the energetics of chemical reactions and their practical applications in various fields.