Why are detergent will heat in water: because there is a kind of chemical substances called NAOH sodium hydroxide. It will releasing heat combines with water. Benzene sulfonate is the main component of detergent ingredients, a lot of material dissolved with the water will produce heat, such as benzene sodium. The real of solid dissolution process is under the action of water molecules to form molecules or ions of solid materials, from the solid part of the formation of hydrated ions and water molecules, which spread to the liquid.
In the process of dissolution, there are two processes: on the one hand, the solute molecules or ions to the water diffusion process, the process needs to absorb heat; the other hand, the solute molecules or ions and water molecules to form molecules or hydrated ion process, the process to release heat, therefore, endothermic, or exothermic dissolution process, key is to see these two compared energy, such as: NaOH water solution, solid, etc., to absorb the heat diffusion process is less than hydrated ions generated during the release of heat, which in general is exothermic; NaCl water solution, solid, etc., to absorb the heat diffusion process and the formation of hydrated ions released during the heat little difference, temperature change; NH4NO3 dissolved solids, etc. in water, the spread is greater than the heat absorbed during the formation of hydrated ions released during the heat, which is generally endothermic.