Which statement best describes an exothermic reaction?

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Multiple Choice

Which statement best describes an exothermic reaction?

The defining feature of an exothermic reaction is that heat is released to the surroundings. In these reactions, the energy of the products is lower than the energy of the reactants by more than is needed to break bonds, and the extra energy comes out as heat, warming the surroundings. That is why you can often feel the container or environment getting hotter. Catalysts can speed up the reaction but don’t determine whether heat is released or absorbed, so they aren’t what defines an exothermic process. Exothermic reactions don’t have to occur at high temperatures; many happen at ordinary temperatures, such as combustion of fuels. In contrast, an endothermic reaction absorbs heat from the surroundings, cooling it. So releasing heat to the surroundings is the correct description.

The defining feature of an exothermic reaction is that heat is released to the surroundings. In these reactions, the energy of the products is lower than the energy of the reactants by more than is needed to break bonds, and the extra energy comes out as heat, warming the surroundings. That is why you can often feel the container or environment getting hotter. Catalysts can speed up the reaction but don’t determine whether heat is released or absorbed, so they aren’t what defines an exothermic process. Exothermic reactions don’t have to occur at high temperatures; many happen at ordinary temperatures, such as combustion of fuels. In contrast, an endothermic reaction absorbs heat from the surroundings, cooling it. So releasing heat to the surroundings is the correct description.

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