Hey all,
At the lectures I noticed that some people weren't feeling very comfortable with some of these topics so I thought I'd put together a quick guide to aid your understanding going into unit 3 and possibly also help you with any Unit 2 assessments you have left. I'll be using spoilers with images in them a fair bit so make sure you click open those. Hope you find this useful and please feel free to follow up with any questions :)
intro to collision theory
(https://i.imgur.com/2dbLjou.png)
(https://i.imgur.com/XdssWpP.png)
When we consider a reaction, there’s going to be some energy already embedded with the reactants. Then, additional energy needs to be provided to meet the activation energy requirements (which will depend on how many bonds need to be broken and strong they are). Next, energy will be released as new bonds are formed and finally, we’ll be left with the energy of the products.
energy profile diagram
(https://i.imgur.com/QJ28sa9.png)
In this example, the reactants had more energy than the products, but equally it could be the case that the products have more energy than the reactants. We represent this difference in energy as the change in enthalpy (ΔH)
exothermic and endothermic
(https://i.imgur.com/ubSvXN7.png)
(https://i.imgur.com/UZbEYgV.png)
If a catalyst is added, this provides an alternative reaction pathway with lower activation energy. Biological catalysts are called enzymes and are made of protein (although they may require non-protein components to function). There are also inorganic catalysts, such as metal nanoparticles.
As you can see, adding a catalyst does not change the value of ΔH
energy profile diagram w/ catalyst
(https://i.imgur.com/2YfzGN7.png)
That's it for now! If you find this useful let me know and I can follow up with more similar resources in future :)
As I said before, please do feel free to reply with any questions. In order to reply you do need to be logged in, if you don't have an account you can register for free here