Endo/exo

[Sienna Webby 2G]

Are all reactions either exothermic or endothermic? Or are there some reactions that do not need or release heat?

[Nancy Stephany Marquez 3C]

I believe that energy is needed to be taken up or released in the formation and breaking of bonds. Therefore the net change will result in either exothermic or endothermic. I believe that there could be a chance that there is no net change in energy, realizing equals the being absorbed, but we may not focus on this during this course.

[Isabella Torriani 2L]

Reactions are endo or exothermic depending on the change in enthalpy (deltaH). Since chemical reactions happen when bonds are being broken and formed, and breaking and forming bonds requires the the input and release of energy, I would think that all reactions need to be exothermic or endothermic.

[Tiffany Wang 2G]

A reaction is endothermic if energy is absorbed and a reaction is exothermic if energy is released. I guess a reaction is neither if energy is not absorbed nor released. But that means that the energy of the products and reactants are the same, which isn't possible unless the same chemical bond is broken and reformed. So all reactions are either endothermic or exothermic.

[Eli Weiss-Hung 2C]

Hello, I believe all reactions are either endothermic or exothermic. Energy is released or required through the forming and breaking of bonds, and if more energy is released the reaction is exothermic while if more energy is required the reaction is endothermic. However, the rearrangement of atoms and bonds should always cause some difference in the energy of each bond and therefore the overall energy, so every reaction should be one or the other.

[Michelle Lim 2G]

Reactions are either endothermic or exothermic I don't believe they can be either. A reaction is endothermic when they absorb energy. Exothermic reactions release energy. When the change in enthalpy is negative, it is an exothermic reaction. When it is positive, it is an endothermic reaction.

[Anjali Mathew 3D]

Reactions are either exothermic or endothermic, since most break bonds or form bonds, and depending on what occurs the net reaction either releases or requires energy. While reactions have activation energies that are required for the reactions to take place, exothermic reactions ultimately release energy, leading to a net decrease in enthalpy, or the delta H. A reaction can be endothermic if there is a net gain in energy, but ultimatley, a reaction is either exothermic or endothermic.

[Reet Padda 1C]

Reactions can be either endothermic or exothermic. To some degree, all reactions require and release energy because of the breaking of bonds (endothermic, energy is required) and formation of bonds (exothermic, energy is released). You can look at the ∆H (enthalpy) of a reaction to see whether it is endothermic or exothermic. A net positive ∆H means that a reaction is endothermic, and a net negative ∆H means that a reaction is exothermic.

[Samuel Vansomphone 1H]

All reactions are either exothermic or endothermic because a reaction requires that either bonds are broken, bonds are formed, or both. Therefore, energy will always either be ended, released, or both depending on the reaction.

[Kush Brahmbhatt 2K]

Typically all reactions would be either endothermic or exothermic depending on the breaking and formation of bonds. The net change of energy required or used in the breaking and formation bonds determines the overall enthalpy which indicates whether the reaction is endothermic or exothermic.

[Julia_Wong_1H]

Yes, all reactions are either endothermic or exothermic. A reaction is endothermic when it requires energy. In contrast, exotheric reactions release energy. Negative enthalpy indicates an exothermic reaction, whereas a positive enthalpy indicates an endothermic reaction. Some change in energy must occur when bonds are broken or created, and all reactions must be endothermic or exothermic.

[205898077]

Yes, all reactions are either endothermic or exothermic, or else it wouldn't be a reaction. For there to be a reaction something has to form or break which releases or absorbs energy.

[Leily Garcia 1C]

Yes, all reactions are either endothermic and need heat to break bonds or exothermic and release light or heat as energy is released. If the sum on enthalpies of the reactants turn out to be greater than the products, then the reaction is exothermic and vise versa for endothermic.

[James Pham 1A]

Since almost all reactions end up with chemical bonds being broken or formed, they must also be either endothermic or exothermic with some non-zero value of enthalpy, unless the energy released and used happen to cancel each other out.

[Kaiden]

Hi,

The answer is yes because all reactions either need energy or release energy because if there was 0 energy lost and 0 energy gained then there would not have been a reaction.

[Helen Heath 2B]

all reactions will be either exothermic or endothermic because a reaction always means a bond is broken or formed and that will always either release energy or use energy

[905775469]

This is correct all reactions are endothermic or exothermic and although in a reaction there are booth bonds formed and bonds broken we want to look at the overall net release or intake of heat (delta H). A reaction is exothermic when it has a negative delta H and releases energy and a positive delta H when it is endothermic and requires energy.

[Camila Garcia 1F]

A reaction has to be either endothermic or exothermic depending on what is being formed or broken during the reaction. For example, the forming of bonds is an exothermic reaction since it releases heat. On the other hand, an endothermic reaction is connected to breaking bonds since you need energy to break them.

[Shiraz Becker 2A]

Hi! All reactions are either exothermic or endothermic. This is because if something is undergoing a chemical reaction, that means bonds are breaking (endothermic) and forming (exothermic). Breaking and forming bonds requires a change in enthalpy, so there aren't reactions that are neither exothermic or endothermic.

[AliciaRoice_1K]

In the context of life science, all reactions release some energy. Hence, in that context, all reactions are exothermic.

I don't believe there is any reaction that produces or releases zero net energy. With the way that chemical systems can be so dynamically altered by factors in the environment, creating an environment where a reaction does not release or produce any energy at all would be extremely difficult.

[Gabriela Alfaro]

All chemical reactions involve energy, whether if the energy is released or absorbed. It is just depends on what is happening in the reaction. If the net enthalpy of the reaction is positive, energy is being absorbed so it is endothermic. If the net enthalpy is negative, it means energy is being released thus the reaction is exothermic.

[Kabir Rahal]

I believe all reactions are either endothermic or exothermic, as all chemical reactions involve a change in energy. Since all reactions either require energy or release energy to break or form bonds, they all must be either endothermic or exothermic.

[Ambar Zamuria 1E]

In order for the reaction to happen, there should be an energy release (exothermic) or gain of energy (exothermic). Meaning that there will be a formation of bonds or a breaking of bonds. If nothing happened, then there is no reaction. Exothermic is ∆H>0 and Endothermic is ∆H<0.

[Kimberly_Wu_3H]

All chemical reactions involve energy, whether it requires or releases it, so all reactions will be endothermic or exothermic.

[Tanaea Taketa 3H]

Since all reactions either require or give off energy, they all are either endothermic or endothermic. All reactions are undergoing either breaking and/or forming bonds. Because

[Kathleen Vo 1G]

If the reaction absorbs heat, it is endothermic. In a chemical equation, this can be seen by a possible (+ heat) included on the reactant side. Delta H in this case would be a positive value. For example. nitrogen + oxygen + heat -> nitrous oxide

If the reaction creates heat, it is exothermic. This can be seen by a (+ heat) included on the product side. Delta H in this case would be a negative value. For example, glucose + oxygen -> water + CO2 + heat.

[405750027]

For any reaction to occur there either has to be energy being released(exothermic) or energy being gained(endothermic). If none were to occur no reaction will occur.

[Michelle_Sen_3H]

Unless some reaction has delta H =0 which is pretty rare, the chemical reaction will be either endothermic or exothermic.
Breaking bonds takes energy and forming new ones release energy.

[Devin Ma 3A]

Whether a reaction is endothermic or exothermic depends on the change in enthalpy. A negative enthalpy indicates an exothermic reaction because it releases energy. On the other hand. a positive enthalpy suggests an endothermic reaction because the reaction requires energy.

[Emily Ng 3D]

Yes, I believe all reactions are either endothermic or exothermic. We learned that the reaction is considered exothermic if the reaction gives a net release of heat, and the reaction is considered endothermic if the reaction requires/takes up heat.

[Daniella Viorato 2G]

All reactions are either endothermic or exothermic. As we know, endothermic reactions require heat/break bonds/have a positive deltaH value and the opposite is true for exothermic reactions. Since the reactions either break or form bonds, they will always be one or the other.

[Rachel Lee]

I do believe that every reaction is either endothermic or exothermic. The release or absorption of heat happens within every reaction and corresponds with the creation and breaking of chemical bonds, respectively. While bonds can both be created and broken apart in a single chemical reaction, it will still be labeled as endo/exothermic depending on the overall change in heat. If a reaction releases more heat than absorbs, it is overall exothermic and vice versa.

[Brandon_Leong_2J]

I believe that all reactions have to be either endothermic or exothermic since all reactions either require an input of energy or release energy to its surroundings. If a bond is broken, energy is required. If a bond is formed, energy is released.

[Graciela Ayala 2I]

If you put it into context for the reaction, that energy does need to be acting on it always otherwise there is no reaction occurring. Even in the case of equilibrium how it's not that the reaction stops, it's that its rate for forward and reverse are equal. So if the reaction is occurring then it will be taking or exerting some energy, since energy can't just disappear or be created out of no where.

[Vincent Cao 2D]

There is a potential for a reaction to be neither endothermic nor exothermic. If you take an equilibrium reaction at equilibrium for example, there will be no net heat change. Thus delta H will be zero across time in the reaction once it's reached equilibrium, as there is no net change in energy. I'm just thinking about this hypothetically, but yes, on the test a chemical reaction will probably be exothermic or endothermic.

[Sophie Vansomphone 1J]

All reactions are either endothermic or exothermic. There is going to either be an input of energy or a release of energy to also break and form bonds.

[Althea Bravo 3E]

All reactions require some type of energy, therefore all will either release or require energy. Furthermore, since every energy reaction is imperfect, there will always be some release of heat.

[Avani Pammidimukkala 2F]

All reactions are either exothermic (releasing heat) or endothermic (absorbing heat), or else no reaction would have taken place. Heat is released when bonds are formed, while heat is absorbed when bonds are broken in a reaction.

[Colin Wong 1C]

Reactions do need to be either endothermic or exothermic as there is always a change in energy to produce something new. If there were no energy change, then were would not be a reaction taking place.

[Ayesha Ashraf]

All reactions require energy changes or the dissociation or formations of bond so if a reaction has occurred you will be able to categorize it as either endothermic or exothermic. This means that a net enthalpy change has to result in either an exothermic (a reaction that releases energy) or endothermic reaction (a reaction that absorbs energy).

[Mariet Garcia 1E]

Yes!
All reactions will either be endothermic or exothermic because during a reaction energy either has to be released or gain.

[CharlotteHilsabe 1B]

Yes, all reactions either require heat or release heat when bonds are formed or broken so they are all either endothermic or exothermic.

[jadensy1L]

Hi! I would think that all reactions either have to be exothermic or endothermic because energy is being released when bonds are broken and energy is required in the formation of bonds.

[Kaitlin Lemke 2K]

Yes!

negative ΔH = exothermic = releases heat
positive ΔH = endothermic = absorbs heat

[Alyssa Gates 1H]

Yup! All reactions are either endothermic or exothermic because they either require or release energy, so it must be one or the other.

[Leily Garcia 1C]

I don’t believe there can be reactions that aren’t endo/exo. There is a standard enthalpy for any one reaction and therefore will result to be exothermic or endothermic depending on the sign of this particular value.

[jkenn123]

Hi, I think you can only have an exothermic or endothermic. In lavelle's lecture where he talks about bonds breaking and forming in order for a bond to break you requires energy whereas forming a bond will release energy. It is in terms of the amount of enthalpy where it is a state value, therefore I don't think it can be anything but endothermic or exothermic.

[Dakshesh Rana 3L]

All reactions need some energy to happen. it can be either exothermic or endothermic.

[Dakshesh Rana 3L]

All reactions need some energy to happen. it can be either exothermic or endothermic.

[Saahithi Kari]

I believe every reaction has a classification of endothermic or exothermic as energy is required and released for every reaction to occur.

[Augustin Kelly 3E]

Because every chemical reaction involves the breaking or forming of bonds, every reaction is either endothermic or exothermic since energy is either absorbed or released. I guess it would be possible for the energy released to equal the energy absorbed, though this would be very unlikely to happen, if at all possible.

[GPena1F]

Are all reactions either exothermic or endothermic? Or are there some reactions that do not need or release heat?

Bond formation in the products of exothermic processes releases more energy than bond breaking in the reactants. The opposite is true for endothermic reactions. And the net energy gain or loss determines whether or not a reaction is exothermic or endothermic.

[Andrew Greenberg 2D]

In order for a reaction to occur a bond must either be broken or formed. If neither of these happens than a reaction has not occurred. If this does happen then it will be either endothermic (breaking bonds) or exothermic (forming bonds).

[Ananya Ravikumar 1I]

Chemical reactions involve breaking old bonds and making new ones. Energy is always needed to break a bond, and energy is released when a bond is formed. These amounts can cancel each other (no net heat absorbed or released), or there can be more absorption of energy than release (endothermic), or more release of energy than absorption (exothermic).

[305568482]

HI, A reaction is usually endothermic or exothermic, this is all based on weather they are absorbing or releasing energy based on if it is breaking or forming a bond.

[Hope_Hayashida_3E]

I would argue that all reactions within real systems are either exothermic or endothermic. I guess technically a system that doesn't absorb or release heat would be neither, but I don't think that would be possible in real life... please correct me if I'm wrong though! :)

[Rebecca_Park_1G]

I agree with all the sentiments expressed above!!

Endothermic and exothermic reactions all revolve around the release/absorption of energy, which is characteristic of all chemical reactions. :)

[405773279]

i always think of it as breaking bonds = need energy = endothermic, forming bonds = release energy = exothermic