Values of E_a = 6.3 kJ/mol and A = 6.0⨉10⁸/(M s) have been measured for the bimolecular reaction: NO(g) + F₂(g) → NOF(g) + F(g) (d) Why does the reaction have such a low activation energy?

Video transcript

Hello. In this problem, we are told an activation energy value of seven Children per mole was determined for the gas phase reaction shown below. We are asked to explain why the reaction has a low value for the activation energy. Let's begin by drawing a reaction profile diagram. So we have energy on the Y axis is a function of reaction progress on the X axis. We have the energy VR reactant to transition state and energy of our products. So this is our reacting energy, our products energy and energy at the transition state. So we are forming bonds and breaking bonds at the transition state. We are forming a bond between the hydrogen and chlorine and we are breaking a bond between the hydrogen and the mean activation energy then is the difference between the energy of our reactant and this transition state a lower activation energy, it means that we have a favorable reaction and the activation energy has to do with energy required to break bones so that we can go on to form new bones. So that means then we are breaking weaker bonds to form stronger bonds. So we are breaking weaker bonds between the hydrogen and the booming and forming stronger bonds between the hydrogen and the chlorine. So if we look at our answers that were given a says, the reaction has a low activation energy because the number of starting and product molecules are just equal again, activation energy has to do with energy associated with breaking bonds. So that we can go on to form new bonds. So it has doesn't have to do with the number of reactant or product. So we eliminate A B says reaction has a low activation energy because molecules involved are gasses. Again, it has to do with the energy associated with breaking bonds so that we can form new bonds. So it doesn't depend on the phase of our reactions to products. The next one says the reaction has low activation energy because hcl bond is weaker and easier to break as compared to the HBR bond. So a favorable reaction means that we'll be forming stronger bonds. That means then that we're forming a stronger bond between the hydrogen and chlorine rather than a weaker bond. So that eliminates. See the correct answer then, is d the reaction has the lower activation energy because the HBR bond is weaker and easier to break as compared to the hydrochloride bond. So again, the lower activation energy says, then that we are breaking this weaker bond and going on to form a stronger bond between the hydrogen, exploring. Thanks for watching. Hope this helps