 But what does this mean or what is the relationship between this this idea and collision theory? Well, here's a little graphic and You'll see quite a number of these in fact This is a great tool for us to analyze systems in equilibrium because when we look at this in terms of the time that so the reaction Proceeding we can see what's going on here. So initially we have no Ammonia in this case we have one mole per liter of Nitrogen and three moles per liter of hydrogen if we were to write this process down hydrogen gas Plus nitrogen gas This time it's an equilibrium. So I'm going to use the double-headed arrow to ammonia Which is also a gas I need to balance this so a two there and a three there will balance it So therefore if I start with if I look at my mole ratio of three to one to two then what I should have in a Completion reaction is the three moles of hydrogen and the one mole of nitrogen should all be used up And I should end up with two moles of ammonia the two moles is here Okay, so this should be here but it isn't and that's telling us that this is an equilibrium not a completion because at some point in Initially we have a high ratio of reactants therefore, we have an a high rate of collision and therefore presumably we also have a reasonably high rate of particles Whose energy is Greater than the energy of activation and therefore they will react but as they react that concentration drops and we start to increase in the number of Ammonia molecules and because two ammonia molecules running into each other will actually reform the hydrogen and nitrogen This will start to occur. So we will we will start with only the forward reaction occurring but as the concentration of the NH3 Starts to increase then we will start to have the reverse reaction starting to occur as well until it reaches a point Where these lines are horizontal and of course? horizontal lines are an indicator of Equilibrium so you can find the point where the equilibrium is first established by finding the point where as the Reaction rates get slower and slower eventually they will reach a point where they are at a consistent rate and There's no more change in the macroscopic properties of the system This is how we we use our understanding of collision theory of particles bouncing into each other Creating chemical reactions And the fact that this occurs not just between the particles of the reactants But also the particles of the products until the rate of both the forward and reverse reactions are identical And then we have equilibrium notice also from this diagram that equilibrium does not mean equal amounts of The hydrogen the nitrogen or the ammonia all we have is a horizontal line Representing that the rates are the same and therefore there's no further change in the Concentration of each of these species