In which type of reaction do products have higher energy than reactants?

In an endothermic reaction, the products indeed have higher energy than the reactants. This occurs because these reactions absorb energy from their surroundings, typically in the form of heat. As a result, the overall energy of the system increases, leading to products with greater energy content. A common example is the process of photosynthesis, where plants absorb sunlight to convert carbon dioxide and water into glucose and oxygen, resulting in products that have significantly more energy stored in their chemical bonds than the reactants.

Exothermic reactions, in contrast, release energy to the surroundings, causing the products to have lower energy than the reactants. Redox reactions involve the transfer of electrons, which may or may not be endothermic or exothermic based on the specific reactants and products involved, and can occur in both energy-increasing and energy-decreasing scenarios. Precipitation reactions typically involve the formation of a solid from solutions and do not directly pertain to the energy changes between reactants and products in the context provided.

Thus, the defining characteristic of an endothermic reaction is the higher energy of the products due to the absorption of energy, making it the correct choice for this question.