Chemical Kinetics part 3

Added: 2026-05-18

[00:00:00]next you will do the factors affecting the rate of reactions in factors affecting the net rate of reaction we will see the nature of the reactants now what are given a nature of the reactants nature of the reacted means see the reactants can be ionic the reactants can be polar in nature so polar means same thing it is similar to that of an equally people average two poles is here isn't it so similar it has got the positive and the negative charges so if it is an ionic inequities polar in nature in that particular case we'll find the rate of reaction is very fast because I said you already breaking up a bond is not involved in the rate of readiness automatically it is very faster just in two separate the electrostatic forces fine but if suppose a chemical bond is in God means in the nature of the reactants is molecule are in the compound this molecule so definitely there is a chemical bond involved in it so when a chemical bond is involved in it you have to break the old one and the formation of new bond is going to take place you have to break the board once so for reading of the old not energies required and the formation of new bond energies released for it difference in energy will give you the energy of the reaction the difference in energy energy or the energy which is required and energy which is released the difference in energy will give you the energy of the reaction alright so in this way what I find is there there it takes some time to carry out the particular reaction so hence nature the reactants place an effective role there whether we have the signal in the reactant side whether it is Ola if it is Pilar overland definitely the reaction will be faster because breaking of a bond is not involved but suppose if the reaction is molecule ah I gave you the reaction of the examples like h2 plus CL 2 gives to axial it is a molecular reaction so you can say that but anyways plus HCl is anything and water it's not a molecular reaction is an ionic reaction that is the reaction to faster in this case be quite slower compared to the the previous reaction we can say any whisper sexy alright so in this way you'll find it out I'll give you another example that is you see yeah like we are having two and no gas plus or to gas we are getting 2 no2 gas this is one range now similarly to Co gas plus o2 gas gives to co2 gas now you see both the reactions are similar I said here nitric oxide reacts it option to give nitrogen exit tunnel now say yes with oxygen to give you carbon dioxide but what do you find is that the first reaction is being faster compared to the second reaction which is slow which is slow reaction is the fast action is a slow reaction to be considered alright this is a fast stretch in this slow reaction why same thing the nature of the bond which is involved now here what you find is that the born here is a become bond here nitric oxide you know nitric oxide uses a nitric oxide is also the but again say this unstable product and carbon monoxide is also an unstable product damn but if the difference in the rate between the two reactions is due to difference in the energies which is involved or it in rearrangement of that particular but it can say the product now here what do you find is that here the when the nitrogen dioxide is being formed the rearrangement is not so much but here when the carbon dioxide is being formed the rearrangement is linear in nature I'll show you see see nitrogen dioxide this is the nitrogen dioxide and what is carbon dioxide this is your carpenter since it is linear it's quite stable structure you know that you have studied in classflow and that I put forward is zero it is quite stable because it is symmetrical in nature it is linear the bottom is 180 degree so what you find is that for the formation of this particular structure some time is required sometimes require you know carbon dioxide according to the structure the car it's very stable structure compared to nitrogen dioxide so here for the formation of this particular structure listen carefully for the formation of this particular structure at some time is required how hence it is being slower but for the formation of this structure the time is not so much required come pay 2,000 extra time is less due to which do the arrangement of the molecule so here the time is differing by gives the arrangement of the molecules here the arrangement of the molecules is linear bonding is 180 degree it is non polar in nature or it is symmetrical in nature so the things is inverted but it is polar in nature it is unsymmetrical in nature Napper bond is non zero so here the formation is not so difficult but here the formation is quite difficult because stable means definitely some more amount of energies released then on the stability fix this you know that energy less 7 it is more because more energies released needs less energy be there in the compound and less energy needs some you give me more so for the release of the energy sometime you will require not so hence it is a slow reaction visit Fox direction so it depends upon water it depends upon the nature of the reactant species because of that clear so in this way the first factor I hope you understood the nature of the reactants the same factories it depends upon the concentration of the reactant species concentration of the reactant we can say that yes if the concentration is more of the rate of reaction be faster if the concentration is less the rate of reaction will be slower how it is how to do it very simple what it is that I take that is test tube to test tubes and it let us see in first test tube I will be taking one bond our valued axial one colored and axial in the second test you same value same value remember at same volume I'll take two more are diluted Co all right now I will put a magnesium ribbon let us say R 2 Center long ignition ribbon I'll insert into its mg magnesium real say here also 2 centimeter long technician ribbon has been inserted can you tell me in which case the hydrogen gas will be released faster in this particular case in this particular case because mg reacts with HCl who gives empty co2 and hydrogen gas is released here also same thing but as the concentration is small here for that purpose what I find is that Triton gases release faster here compared to this how can we know I didn't guess this release faster take a bunny splinter bring it near the mouth of the two test tubes you will see in this case the bunny splinter goes off with the boxart in this case first the bunny splinter goes up with a pop sort compared to this so it proves by this only the Guardian gas is the world faster compared to this particular one so here what I find is that as a concentration is more the rate of the reaction is faster same thing if you are burning to handle this one in a gas jar of oxygen and another in air which will burn faster the one which is burning in oxygen because air is dilute but when I say gasps sheriff oxygen means it contains 100 percent of oxygen but when I say it means it does not contain hundred percent you know that 20 percent is oxygen is there a remaining 80 percent is some other gases so the air is in case of air the oxygen is diluted look so you this really body find is that as a concentration increase the rate of the reaction also increases okay so what do you find here the concentration rate of reaction is directly proportional to concentration here and here also same thing rate of reaction is directly proportional to the nature of the reactants which is involved next is after that we will see the size of the reacting species the science of the reacting species all right now definitely the size also effective road signs of the reactant species suppose if I take pieces of wood and if I take a log of wood which will burn faster definitely piece of wood well because piece of wood means smaller and lower means a bigger one it's like let's suppose when you're going for a picnic i cutting a tree and putting it into the kitchen are you are getting small pieces you have chopping small pieces of what Aeneid putting into the cable we are we are chopping small pieces and we are putting into the tuna isn't it that son killed we can say so hence similarly suppose if we want to dissolve like if we want to dissolve sugar ND and if you want to dissolve sugar in a glass of water which will dissolve faster sugar because size of the sugar particles is smaller compared to that of so they're kinda so we can take this misery alright so Stewart candy will dissolve at a slower rate but sugar will dissolve faster big answer that similarly if you be charcoal and if you take coke which will burn faster charcoal will a charcoal means to dust you cancel that coke dustfinger so that other words and coal means or oak makes it's a lump it's a big piece we can say that so that will burn slowly say in this way when you find a certain size are the reactant plays an effective role here so if your size is smaller the surface area is bigger already the size is small the surface it will be big suppose if you take an wood this much amount of food so the area if you put it in the flow rate somewhere the area will be much more all right but if you take a lava good it will covers very small area so the surface area increases the rate of reaction increases or when the size of the reactant decreases the rate of reaction increases so rate of reaction is inversely proportional to that size of reactant species the rate of reaction is inversely proportional to the size and species if the size of reactant species is smaller the rate will be facets inversely proportional all right I hope you understood this now next is it also depends upon that beliefs your catalyst no it's a work of the catalyst khakis provides an alternate path to tell you the rich it provides an alternate path what is in the alternate path suppose if I do a particular reaction alright if I do a particular reaction let us say rate against what it can say time listen okay so what do you find is that if I take a catalyst then the timings are progressively and select minute that's a better word instead of writing time let me write progress of reaction yeah that's a better word so what do you find is that this is without a catalyst the graph is this is a graph let me start from here a little bit this is your this is nothing but for the rate for the reactant and this is for the product we can say that this is for the product or instead of rate if I take energy that will be much better because I was talking about energy now anything you already don't take a rate against time rate against progress of reaction building or any against progress of the action you can take it let us say this is energy of the reactant and let us say this is the energy of that product legacy now this graph have done it without catalyst without catalyst now what is a catalyst provides an alternate path now what do you think whether alternate paths alternate path means see this is an alternate path now when you take a catalyst what do you find is that you know the if it is a positive catalyst the reaction be faster so this is the alternate path see this is the alternate path it is being provided by the catalyst so what is the energy is required now initially this was zero threshold energy this was your threshold a logistic this is the energy of reactant so it has to reach this level then after that minimum threshold energies are the minimum amount of energy which is Macario variation this is your threshold energy e the H means threshold threshold means energy one less soul or even where the world threshold resolving is the minimum amount of energy which is required to kameoka reaction because we know that energy of the reactant is as much and most of the reactions you know it is not carried out at room temperature it is carried out an elevated temperature means you eat it there are three actually scarier most of the rich 99% of the reactions you can see except ionic reaction which is carried out at room temperature otherwise most of the reactions if we eat slightly slightly related at least have to vomit there are the reaction is carried out okay so you have to provide some extra amount of energy see this is energy of the reactant now this is this is not sufficient to carry out the reaction so I have to provide this excess amount of energy I will tell you also what is this excess amount of energy Scott so I have to provide this excess amount of financial they know if the reaction will be carried out so what is the threshold energy is required for this reaction without catalyst this is the threshold energy now see with at least the graph is this the blue one you can see the graph now what is the threshold energy this is the threshold energy second this much is a Tercel damage and with PAOK acted with calculus without catalyst this is the president isn't it see ya and here what is the threshold energy this one is the threshold event see from here to here okay so which is more threshold energy in which the energy required more to carry out a particular reaction in the first case this is with catalyst the blue one the graph are you getting me what I am saying this graph the black one it is without catalyst this is the threshold energy required but when I when I take a catalyst then this is the graph because what I said you Kathie's means which provides an alternate path to carry out the reaction see this is an alternate path so now this is the energy resident so here the energy is less or here than it is less definitely Smith can taste so hence when you take a catalyst the ladies in the world and hence the reaction because faster all right when you take a catalyst this is a graph with a catalyst so see the energy takes energy which is required the minimum energy which is required is lowered and here see the main energy is increased with the without catalyst so by taking a catalyst what happens again I repeat the energy is lower the minimum amount of energy should be greasing the wheels the reaction becomes faster it's completed faster now is telling you that this is your energy of the reactant this much so this is this is your threshold energy etc dacia market now this is the excess of our definite it is a difference between threshold energy and energy of the reactant so what is that energy corridors for us activation energy e EI EI is equal to EP h - e i again i repeat this is a energy of the reactant and this much is your minimum energy which is required so I have to give an excess energy to carry out the reaction so that excess energy is called as activation energy so you can also say that when you are carrying out reaction pit with the catalyst activation energies less and without catalyst activation which is more that's it so in this way by taking a catalyst what I find is that the rate of reaction becomes faster because the energy which excess which is required is less due to base the reaction becomes faster thank you very much