Exothermic Examples

[Marnie Cavanaugh- 1A]

In the lecture we were given that the phase changes- vaporization, melting, and sublimation are all endothermic reactions. Are there any phase changes that are exothermic?

[Angela Hung 1H]

Freezing and condensation are two examples of exothermic phase changes, because they involve the release of energy through the formation of bonds.

[jhb123]

Hello!

Lavelle had mentioned that exothermic phase changes would take place in the reverse reactions of the processes you've mentioned. For example, freezing would be an exothermic reaction, as heat energy is released (causing the molecules to condense); this, of course, would be the opposite of melting. Condensation is the opposite (reverse reaction) of vaporization, as gas turns to a liquid. This, too, is an exothermic reaction.

Hope this helps :)

[Kailyn Kennada 3E]

Hi there! Yes there are 3 examples of phases changes which are moving in the opposite direction where energy is released. These include Freezing (Liquid to Solid), Condensation (Gas to Liquid), and Deposition (Gas to Solid directly). Visually imagining all of these phase changes in regard to weather like rain or snow has always helped me to visual it in my mind. Hope this helps!

[BeauBrown]

any of those phase changes in reverse would be exothermic (liquid to solid, gas to liquid)

[Natalie Hurd 1H]

Yes! The opposite reactions to all of those endothermic reactions would be exothermic. This would mean condensation (vapor -> liquid), freezing (liquid -> solid), and deposition (vapor -> solid) would all be exothermic reactions.

[Frankie Xu 2H]

Exothermic reactions are when heat is released so the surroundings get hotter so a phase change would be in condensation when it goes from vapor to liquid and freezing from a liquid to a solid.

[Katherine Phan 1J]

The opposite phase changes are all exothermic: condensation, freezing, and deposition. A quick way to remember which phase changes are endothermic and which are exothermic is "takes to break" and "frees to form." Those that require the breaking of intermolecular forces are endothermic because it takes energy to break whereas those that involve the formation of intermolecular forces are exothermic because they release energy.

[Catherine Grigorian 3L]

In the lecture, professor focused mainly on endothermic reactions, which are reactions that require heat. He mentioned vaporization, melting, and sublimation. All of these share in common that the molecules inside go from a state of being more constricted, where it can not move as much, to a state of where the molecules move more. Therefore, heat needs to be added to allow the higher energy, to allow for the molecules to move more. Let's take melting for example. In solid ice, the molecules cannot move, but in liquid they can move so you put heat in the system to get the molecules to move more, becoming liquid. For exothermic, think of this in reverse. Exothermic means that it releases heat. These can include condensation, freezing, and deposition. In all of these processes, the substance goes from a state of more molecule movement to a state with less molecule movement. Therefore, to cause less movement, there needs to be less energy, therefore heat must be removed. This heat then leaves the system and enters the surroundings/environment. Let's think of freezing. The liquid water has more movement in its molecules and ice has less movement, therefore you must release heat/energy in order for freezing to occur.

[Kushal Chatterjee 1J]

Since vaporization (liquid to vapor), melting (solid to liquid), and sublimation (solid to vapor) are all endothermic phase changes, any of these phase changes in reverse would therefore be exothermic. Going from liquid to solid, for example, is exothermic, and this is known as freezing. Going from vapor to liquid is exothermic, and this is known as condensation. Going from vapor to solid is exothermic, and this is known as deposition.

[joannar]

Hi!

Yes there are 3 main phase changes that are exothermic, and this includes; freezing, condensation, and deposition, which are pretty much the reverse of fusion, sublimation, and vaporization!

[Shiraz Becker 2A]

If you reverse sublimation, vaporization, and fusion (which are all endothermic) then you will get exothermic reactions. Condensation, freezing, and deposition are these reverse reactions and are exothermic.

[Elliana_Tsang_1L]

The opposite of the phase changes you listed are exothermic. Condensation which is gas to liquid, freezing which is liquid to solid, and deposition which is gas to solid all release energy. In terms of quantifying enthalpy for a respective substance, the exothermic processes have the same magnitude as their opposite phase change, but the value is negative. The reactants have a higher energy than the products.

[Alyson Chou 3H]

Freezing and condensing would be exothermic since exothermic is the release of heat

[Min Hur 1L]

Pretty much the reverse reactions of the ones you have listed, which would be freezing and condensing, are examples of exothermic reactions!

[Camila Garcia 1F]

Some exothermic examples that exist include freezing and combustion. Since these reactions are releasing energy, they are considered to be exothermic reactions.

[Octavio Santana 2H]

Exothermic phase changes would be the reverse of all those phase changes! Specifically, condensation, freezing, and deposition are all phase changes that are exothermic. This is because these phase changes involve the release of energy, which is what exothermic means.

[Valerie Jun 2D]

Exothermic reactions are reactions that give off heat! I like to think of it as the opposite of endothermic and I know that endothermic reactions require heat so something like melting ice or condensation requires heat so freezing is exothermic!

[Tanaea Taketa 3H]

Some examples of exothermic reactions are water condensing or a car using gasoline. Condensation and freezing are also examples of exothermic.

[Madhavi Akella 2H]

Yes! Freezing, condensation, and deposition are all exothermic reactions. They are also the opposite of melting, vaporization, and sublimation.

[SameeraGurram1]

Exothermic reactions release heat, so when you think of examples you have to think with this perspective of losing/releasing heat. Like when something freezes, it is becoming colder, so it is losing heat, which means it releases heat. Hopefully that helps better understand examples of exothermic reactions!

[Yuliana Urrutia 1H]

hello, the reverse actions of those endothermic reaction would be considered exothermic, for example going from liquid to solid, and gas to liquid since they require heat

[Sydney Tanimitsu 2B]

Some examples would be freezing or condensation, or when you take the reverse reaction of an endothermic reaction (the opposite of gaining heat would be loss of heat if that helps to think of it that way)

[Camilla Hinrichsen 1A]

There are actually a few phase changes that are exothermic. The changes freezing, deposition, and condensation, are all phase changes that are exothermic. This is because in these cases, heat energy is leaving (or "exiting" if that helps you remember it's exothermic!) the system into the surroundings, which makes the change an exothermic one. These are also the opposites of fusion (melting), sublimation, and vaporization which are the endothermic changes we learned in class.

[Jeanelle Ocampo 2L]

Hi!

For exothermic phase changes you have:
liquid to solid (freezing), gas to liquid (condensation), gas to solid (deposition)

For endothermic phase changes you have:
solid to liquid (melting), liquid to gas (boiling), solid to gas (sublimation)