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
Ok...an exothermic reaction is a type of chemical reaction that releases heat energy to the surrounding, so definitely it is hot when you touch it (exo=release, thermic=heat). You can try that by mixing water and sodium hydroxide pellets in a flask and you will feel that the flask gets hotter which indicates the reaction to be exothermic. burning fuels or combustion reactions are examples of exothermic reactions. it is that simple, but the complication is when you are dealing with the energy diagram where you will see a drop in energy though you feel heat from the mixture!!!. keep in mind that the heat you feel is the one that been released to the surrounding i.e. the flask. so externally, heat energy is increased, but internally for a system, heat energy is decreased because it is been given out to the surrounding. The energy diagram only shows the energy profile for the internal system not the surrounding.
an opposite to exothermic is endothermic (endo=into) and you can prove that by mixing water and ammonium chloride..the flask will get colder because, heat energy is been absorbed from the surrounding, so the heat moves from the surrounding (flask or air) to the system so you felt that as cold. but internally, the system is higher in energy.
hope that helps sorry for too long description...
Ah ok, makes sense, thank you :) Also one more question if you don't mind, which produces more energy, exo or endo? Or does it depend on the delta H it gives you in the equation?
the delta H in the equation indicates the type of reaction exo or endo. a positive value means an endo whereas a negative value means an exo rxn..in terms of energy been dissipated, exothermic reaction are more effective in producing more energy, and they are our main source of heat in our everyday life such as respiration. Endo reactions are sometimes used in medical purposes such as ice-bags where you just crushed the back containing water and salt (such as ammonium chloride) to generate coldness to apply on minor injuries and even used for temporary cooling of water bottles etc..so in terms of energy storage, endo reactions mostly suited...
hope that helps...
Yes, so in other terms, you are saying that exothermic reactions usually generate more, but endothermic reactions store more?
yeb
When an endothermic reaction occurs, it typically feels cold because it absorbs heat from its surroundings. This happens because the reactants in an endothermic reaction require an input of energy to break the bonds holding them together, and this energy is typically taken from the surrounding environment. The energy absorbed reduces the temperature of the surroundings, making it feel colder.
To determine if a reaction is endothermic or exothermic, you should first check the overall energy change associated with the reaction. If the products have more energy than the reactants, then the reaction is endothermic because it has absorbed energy. Conversely, if the products have less energy than the reactants, then the reaction is exothermic because it has released energy.
One way to measure the energy change is by monitoring the change in temperature during the reaction. If the temperature increases, it indicates an exothermic reaction because heat is released into the surroundings, making it feel hot. On the other hand, if the temperature decreases, it indicates an endothermic reaction because heat is absorbed from the surroundings, making it feel cold.