Combining Lead Nitrate and Potassium Iodide
Lead Nitrate and Potassium Iodide react to form Lead Iodide and Potassium Nitrate. The reaction can be represented by the following chemical equation:
Pb(NO3)2 + 2KI → PbI2 + 2KNO3

Exothermic or Endothermic?
- Exothermic Process: When a reaction releases heat to its surroundings, it is considered exothermic. In this case, the formation of Lead Iodide from Lead Nitrate and Potassium Iodide is an exothermic reaction. This is because the energy released when the new bonds form between the atoms in the products is greater than the energy required to break the bonds in the reactants. As a result, the excess energy is released in the form of heat.
- Endothermic Process: Conversely, an endothermic process absorbs heat from its surroundings. This means that the energy required to break the bonds in the reactants is greater than the energy released when the new bonds form in the products. As a result, the reaction absorbs heat from the surroundings to compensate for this energy difference.
In the case of the reaction between Lead Nitrate and Potassium Iodide, the process is exothermic because heat is released during the formation of Lead Iodide. This release of heat can be observed by an increase in temperature in the surroundings during the reaction.
In conclusion, combining Lead Nitrate and Potassium Iodide is an exothermic process, as heat is released during the formation of Lead Iodide.