Ok, so in an when an endothermic reaction occurs, is it hot or cold? and why? Also what is it for an exothermic reaction? Thank you
When an endothermic reaction occurs, it absorbs heat from its surroundings, so it feels cold. To understand why this happens, we need to look at the concept of energy exchange in chemical reactions.
Endothermic reactions involve breaking bonds in reactant molecules and forming new bonds to produce products. This process requires an input of energy to overcome the energy barrier between reactants and products. As a result, the reaction absorbs heat energy from the surroundings to provide the necessary activation energy required for the reaction to proceed.
For example, let's consider the reaction between ammonium nitrate (NH4NO3) and water (H2O), which is commonly used in cold packs. In this reaction, NH4NO3 reacts with water to form ammonium ions (NH4+) and nitrate ions (NO3-). The dissolution of ammonium nitrate in water requires energy, which is absorbed from the surroundings, resulting in a decrease in temperature near the reaction mixture. Hence, it feels cold.
On the other hand, exothermic reactions release heat energy to the surroundings, which makes them feel hot. In an exothermic reaction, the formation of new bonds in the product molecules releases more energy than is required to break the bonds in the reactant molecules. The excess energy is released as heat, raising the temperature of the surroundings.
For example, the combustion of natural gas (CH4) is an exothermic reaction. When methane reacts with oxygen (O2) in the presence of a flame, it produces carbon dioxide (CO2) and water vapor (H2O), releasing a significant amount of heat energy in the process. This heat energy warms up the surrounding environment, making it feel hot.
In summary, endothermic reactions feel cold because they absorb heat from the surroundings, whereas exothermic reactions feel hot because they release heat energy to the surroundings.