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### Le Chatelier's and Endo/Exothermic

Posted: Mon Jan 06, 2020 9:53 pm
What is an easy way to remember which side of the chemical equation heat is on? Also, why do exothermic equations have a negative value?

### Re: Le Chatelier's and Endo/Exothermic

Posted: Mon Jan 06, 2020 10:32 pm
Exothermic means energy is released while endothermic means energy is taken in, so exothermic:energy is a product, and endothermic: energy is a reactant. What I use to help me determine which is which is to think that endo sounds like "in", so it takes in energy.

In exothermic reactions, energy leaves the system, so the system has less enthalpy than it did initially, meaning a negative enthalpy value.

### Re: Le Chatelier's and Endo/Exothermic

Posted: Tue Jan 07, 2020 11:29 am
In high school, I remembered exothermic to be related to the word exterior, so the heat comes to the outside and is, therefore, is released to the exterior of the system. Endothermic is the opposite.

### Re: Le Chatelier's and Endo/Exothermic

Posted: Tue Jan 07, 2020 4:39 pm
Exothermic equations have a negative value because heat energy is being released into the environment, and the enthalpy of the products is lower than the reactants.

### Re: Le Chatelier's and Endo/Exothermic

Posted: Wed Jan 08, 2020 8:11 pm
We won't be expected to just look at a chemical equation and know which side the heat is on, instead we will get an energy value. If the energy value is negative, then the heat is on the right, it is being lost. If the value is positive, then heat is being added to the system as a result of the forward reaction, and it is on the left.

### Re: Le Chatelier's and Endo/Exothermic

Posted: Thu Jan 09, 2020 5:33 pm
for exothermic, heat is released which makes it a product.
for endothermic, heat is absorbed which makes it a reactant.