Exothermic vs. Endothermic


Moderators: Chem_Mod, Chem_Admin

Kennedi2J
Posts: 101
Joined: Wed Sep 18, 2019 12:20 am

Exothermic vs. Endothermic

Postby Kennedi2J » Sun Mar 08, 2020 8:50 pm

By looking at energy profiles, how can you tell if it is showing an endothermic or exothermic reaction?

Nicholas Chin 1G
Posts: 100
Joined: Thu Jul 11, 2019 12:17 am

Re: Exothermic vs. Endothermic

Postby Nicholas Chin 1G » Sun Mar 08, 2020 8:55 pm

Generally, if the reactant energy is higher than the product energy, the reaction is exothermic, and vice versa for endothermic.

VLi_2B
Posts: 99
Joined: Sat Sep 14, 2019 12:15 am

Re: Exothermic vs. Endothermic

Postby VLi_2B » Sun Mar 08, 2020 9:00 pm

This is a good video explaining exothermic vs endothermic reactions.
https://www.youtube.com/watch?v=JRIm_a2LDPM

Radha Patel 4I
Posts: 97
Joined: Tue Feb 12, 2019 12:15 am

Re: Exothermic vs. Endothermic

Postby Radha Patel 4I » Sun Mar 08, 2020 9:00 pm

When the reactants activation energy is higher than the products, then it is exothermic. In this case, potential energy is higher for reactants than products. When the products activation energy is higher than the reactants, then it is endothermic. In this case, the potential energy of the reactants are lower.

Lauren Tanaka 1A
Posts: 109
Joined: Sat Aug 17, 2019 12:18 am

Re: Exothermic vs. Endothermic

Postby Lauren Tanaka 1A » Sun Mar 08, 2020 9:01 pm

You can tell it is exothermic when the activation energy is higher for reactants than it is for products. If the activation energy for products is higher than for reactants then the reaction is endothermic.

KHowe_1D
Posts: 103
Joined: Thu Jul 25, 2019 12:15 am
Been upvoted: 1 time

Re: Exothermic vs. Endothermic

Postby KHowe_1D » Sun Mar 08, 2020 9:04 pm

When reactant energy is higher than the product it is exothermic because energy is being released but if the reactant energy is lower than the product, it is endothermic because energy is required.

Hannah Pham
Posts: 104
Joined: Fri Aug 09, 2019 12:17 am

Re: Exothermic vs. Endothermic

Postby Hannah Pham » Sun Mar 08, 2020 9:04 pm

It is an exothermic reaction when the activation energy of the reactants are higher than the products. If the activation energy of the products is higher than the reactants, then it is an endothermic reaction.

AronCainBayot2K
Posts: 101
Joined: Fri Aug 30, 2019 12:17 am

Re: Exothermic vs. Endothermic

Postby AronCainBayot2K » Sun Mar 08, 2020 9:16 pm

If activation energy is higher than products, exothermic. If higher than reactants, endothermic.

saigorijavolu2k
Posts: 108
Joined: Sat Sep 28, 2019 12:15 am

Re: Exothermic vs. Endothermic

Postby saigorijavolu2k » Sun Mar 08, 2020 9:22 pm

An exothermic reaction is one where the reactants have more energy than products. Exothermic releases energy, which is why the reactants should have more energy.

Nare Nazaryan 1F
Posts: 101
Joined: Fri Aug 09, 2019 12:17 am

Re: Exothermic vs. Endothermic

Postby Nare Nazaryan 1F » Sun Mar 08, 2020 11:16 pm

If reactant energy is higher than the product energy, the reaction is exothermic and the opposite for endothermic.

Adriana_4F
Posts: 74
Joined: Fri Sep 28, 2018 12:29 am

Re: Exothermic vs. Endothermic

Postby Adriana_4F » Sun Mar 08, 2020 11:17 pm

Also just to add on, If the enthalpy is negative, the reaction is exothermic because heat is being released. If the enthalpy is positive, the reaction is endothermic because heat is being taken up by the rxn

Simon Ketema_1F
Posts: 16
Joined: Wed Nov 13, 2019 12:26 am

Re: Exothermic vs. Endothermic

Postby Simon Ketema_1F » Sun Mar 08, 2020 11:18 pm

A reaction is exothermic when the energy of the reactants is higher than the energy of the products. The energy difference is what is released into the surroundings as heat.

A reaction is endothermic when the energy of the reactants is lower than the energy of the products. The energy difference is what is required from the surroundings for the reaction to occur.

Shrayes Raman
Posts: 129
Joined: Sat Jul 20, 2019 12:15 am

Re: Exothermic vs. Endothermic

Postby Shrayes Raman » Sun Mar 08, 2020 11:48 pm

Exothermic reactions will have reactants higher than products and vice versa for endothermic.

Jarrett Peyrefitte 2K
Posts: 102
Joined: Sat Aug 24, 2019 12:16 am

Re: Exothermic vs. Endothermic

Postby Jarrett Peyrefitte 2K » Sun Mar 08, 2020 11:54 pm

A reaction is exothermic when the reactants have more energy than products. Vice verso for endothermic.

J Medina 2I
Posts: 102
Joined: Wed Sep 25, 2019 12:17 am

Re: Exothermic vs. Endothermic

Postby J Medina 2I » Sun Mar 08, 2020 11:57 pm

With reaction profiles to get delta H you have to subtract the end of the graph (products) by the beginning of the graph (reactants). So you have to remember that EXOTHERMIC reactions release energy into their surroundings meaning there is a loss of energy from the system ( meaning delta H = - ). So for exothermic reactions the end of the graph has to be lower than the beginning of the graph. And for ENDOTHERMIC reactions the end of the graph has to be higher than the beginning of the graph.


Return to “Reaction Mechanisms, Reaction Profiles”

Who is online

Users browsing this forum: No registered users and 2 guests