Final answer:
A reaction with products that have stronger bonds than the reactants is exothermic, releasing more energy than it absorbs and causing the surroundings to warm up. The enthalpy change for such reactions is negative.
Step-by-step explanation:
When we consider a chemical reaction where the products have stronger bonds than the reactants, we are dealing with an exothermic reaction. In such reactions, more energy is released in forming the product bonds than is required to break the bonds in the reactants. The excess energy is usually released as heat, causing the surroundings to get warmer.
The enthalpy change (ΔH) for an exothermic reaction is negative, indicating that heat is produced as the reaction proceeds. Conversely, an endothermic reaction occurs when the products have weaker bonds than the reactants. For these reactions, bond-breaking absorbs more heat than bond-making releases, resulting in a positive ΔH, and energy is absorbed from the surroundings.