## Exothermic vs. Endothermic

Arrhenius Equation: $\ln k = - \frac{E_{a}}{RT} + \ln A$

Olivia L 4E
Posts: 59
Joined: Fri Sep 28, 2018 12:23 am
Been upvoted: 1 time

### Exothermic vs. Endothermic

If a reaction has activation energy, is it always endothermic? If not, is it because deltaG plus the activation energy is still less than zero? or is there something else?

Posts: 57
Joined: Fri Sep 28, 2018 12:27 am

### Re: Exothermic vs. Endothermic

All reactions use activation energy, but exothermic reactions just produce more energy than they consumed. So to answer your question, having activation energy does not declare a reaction being endothermic vs exothermic. They could have the same Ea, but they depend on the initial and final energy use. Exothermic has a negative G, while endothermic has a positive G.

Megan_Ervin_1F
Posts: 78
Joined: Fri Sep 28, 2018 12:18 am

### Re: Exothermic vs. Endothermic

An endothermic reaction has a higher energy barrier in the forward direction so k forward is greater than k reverse which means that if you heated up a endothermic reaction the k forward would increase so the K overall would also increase and products would be favored

For an exothermic reaction, the activation energy is lower in the forward direction so if you heat up an exothermic reaction k reverse will increase which will result in a lower K and the reaction will favor reactants

Salena Chowdri 1I
Posts: 66
Joined: Fri Apr 06, 2018 11:02 am

### Re: Exothermic vs. Endothermic

Both endothermic and exothermic reactions have Ea, however endothermic reactions will have a larger energy barrier to go over.

hanna_maillard3B
Posts: 61
Joined: Fri Sep 28, 2018 12:23 am

### Re: Exothermic vs. Endothermic

a reaction is endothermic is the E(a) (activation energy) of the forward reaction is higher than the reverse reaction. therefore, if the temperature increases, the rate constant of the forward reaction will increase because k is dependent on temperature.

Jacqueline Duong 1H
Posts: 61
Joined: Fri Sep 28, 2018 12:28 am

### Re: Exothermic vs. Endothermic

Every reaction has activation energy since it is the minimum amount of energy needed to be able to undergo the reaction. Activation energy is the difference in the energy between the transition state and the reactants.

Megan Kirschner
Posts: 46
Joined: Wed Feb 20, 2019 12:17 am

### Re: Exothermic vs. Endothermic

An exothermic reaction- the activation energy is lower in the forward direction so if you heat up an exothermic reaction k reverse will increase which will result in a lower K and the reaction will favor reactants

Rosa Munoz 2E
Posts: 105
Joined: Wed Sep 18, 2019 12:21 am

### Re: Exothermic vs. Endothermic

Activation energy plays a role in both.

205150314
Posts: 106
Joined: Wed Feb 20, 2019 12:16 am

### Re: Exothermic vs. Endothermic

activation energy is in both types of reactions

CalvinTNguyen2D
Posts: 102
Joined: Thu Jul 25, 2019 12:16 am

### Re: Exothermic vs. Endothermic

All reactions will have some sort of activation energy. What determines if a reaction is exothermic or endothermic is the final value of the amount of energy still within the system.

kristi le 2F
Posts: 102
Joined: Thu Jul 11, 2019 12:15 am

### Re: Exothermic vs. Endothermic

Endothermic and exothermic reactions both have an activation energy. But for endothermic reactions, the products have higher energy than the reactants and for exothermic reactions, the products have lower energy than the reactants.

Return to “Arrhenius Equation, Activation Energies, Catalysts”

### Who is online

Users browsing this forum: No registered users and 1 guest