When something melts, boils, evaporates or sets fire.
An endothermic reaction is one in which thermal energy, or heat, is absorbed. If heat is absorbed in the reaction process, it is endothermic. By monitoring the temperature of the reactants in a reaction, an observer could identify an endothermic reaction through observation of a decrease in the temperature.
An endothermic reaction absorbs heat from its surroundings, while an exothermic reaction releases heat to its surroundings. The general formula for an endothermic reaction is: reactants + heat → products, and for an exothermic reaction: reactants → products + heat.
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Endothermic means that a reaction needs heat to occur. Limestone needs to be heated to decompose into calcium oxide and carbon dioxide
endothermic but don't know why? As AN crystals are formed the reaction is exothermic. Endothermic when it melts back with water. This is the reason AN is used in cold packs.
Sounds like a homework question. We know that in an exothermic reaction, heat is taken out of the system and given to the surroundings. Whereas in an endothermic reaction, heat is pulled from the surroundings into the system. I am assuming you are thinking of the cookies as the system. So in this case, energy--in the form of heat--is being taken out of the oven and being put into the cookies. The cookies, using the energy increase in temperature, which bakes the cookies, creating the tasty little morsels of joy that cookies are.
The temperature will decrease.
The reverse reaction is not always endothermic or exothermic, the reverse reaction is the opposite of whatever the initial reaction is, so if the reaction is endothermic, the reverse reaction is exothermic and vise versa.
No, the reaction between copper sulfate and hydrochloric acid is exothermic, meaning it releases heat. This is because energy is released when the products are formed, making the overall reaction exothermic.
It is impossible to know without more information.
in an endothermic reaction the reacting substances are releasing energy, making them feel cold. i don't know what you mean by evaporating heat, but you cannot create or destroy energy if that helps.
Changes in color: If the color of the reactants or products changes during the reaction, it is a sign that a chemical reaction has occurred. Formation of a gas: Production of gas bubbles or fizzing indicates a chemical reaction, such as in the reaction between an acid and a carbonate. Changes in temperature: If the reaction absorbs or releases heat, causing a change in temperature in the surroundings, it signals a chemical reaction has taken place.