 Okay, next one right down. Third one, Animes. Yes, that chap is done. This next chap. Last day I forgot that, otherwise I would have finished last class only. That Maxwell's equation. Gas equations which one? TV's also NRT. Yes, you will have some equations. You'll have that. Today only I think. You can solve those questions. On the group you can check. Okay, what is thermodynamics? See, thermodynamics, thermo means heat. And dynamics means what? Motion or flow. So in this chapter we study about the flow of heat or the motion of heat. How the heat flows. So we are going to study about the flow of heat. In this chapter we are also going to understand whether the reaction is spontaneous, spontaneity. What is the spontaneous process that we are going to understand? What are the different processes we have? Right, by which the state of thing changes. So flow of heat, spontaneity and process. So thermo dynamics, this is another chapter in which we deal with chemical reactions. Chemical reactions we have three different chapters actually. Thermo dynamics is one of the chapters. Chemical equilibrium, chemical kinetics. These three chapters we are going to study to understand the chemical reaction properly. Thermo dynamics gives you the information about spontaneity of a reaction. Like C is chemical equilibrium, T is thermo dynamics, C is chemical kinetics. So these three chapters we are going to study about chemical reaction in these three chapters. Now what is the uses of this? Thermo dynamics gives us the information that under a given set of conditions whether the reaction is possible or not. So what is the condition for a reaction to be feasible? And for that we have delta G, gives free energy. Delta G should be what? Delta G should be less than zero for any spontaneous reaction and I will discuss how. So this chapter gives us the information about the spontaneity of any reaction. Chemical equilibrium deals with the direction of reaction, whether the reaction goes into forward direction or backward direction. So this gives you the information of direction of reaction, in which direction the reaction proceeds obviously under a given set of conditions. Chemical kinetics deals with the rate of reaction. Rate of reaction means what? At what speed the reaction is proceeding. After what time the reaction gets finished. All these three different chapters we have which deals with the chemical reactions. So in this chapter we are going to understand about a given reaction and feasibility of that reaction. So there are few terms in this chapter but that we have to understand first. And the first term we have here is system. What is the system? What is surroundings? System and surrounding. What is the definition of a system? Under consideration. Under consideration. It is anything, it is a part of the universe which is under consideration. System plus surroundings is equals to the universe. Right? Right now system is anything which is under consideration. Okay? Surroundings is what? Surroundings which interacts with, it is again the part of the universe which interacts with system. So suppose you have this universe and in this a beaker is there, in this beaker we have some gases molecules present. Right? So we are trying to understand or read the properties of this gases molecule. This gases molecule is the system. Right? Apart from this gases molecules everything is what? Surroundings. And both this collectively called as universe. Okay? This is which separates the system and surroundings. This part we call it as what? The boundary. Boundary. Boundary is what? Which separates the system with surroundings. Okay? Now this boundary can be what? It can be? Yes. It can be adiabatic? It can be insulated? Or it can be what? Isolated. No that's not right. Permeable we can say, we can say diathermic also. There are many different things we will see that. Okay? Systems again it can be an open system, it can be a closed system, it can be an isolated system. So there are three types of system we have. So write down. There are three types of system possible. The first one is an open system. What is an open system? Energy and matter. Which can transfer both matter and energy. Okay? Open system transfers both in short to write on transfers both matter and energy. Next write down closed system. Exchange of only energy possible. There is no exchange of matter in this because the system is closed. There is no exchange of matter only exchange of energy. Isolated system. No exchange of matter and energy. No exchange of matter and energy. Okay? So only matter cannot be exchanged. It's in a closed system. When the system is closed, then only energy can exchange. When the system is closed, then only energy exchange. Because system is closed. So all these gases particles cannot come out. But it can, you know, radiates the energy. Heat energy can radiate. Okay? If it is isolated, means there is no transfer of energy also possible. Closed if it is there, then matter obviously cannot transfer. Okay? Now the next thing, write down next, state variable. What we use to define the state of a system. Okay? Like in gases and state, the variables are what? Pressure, volume and temperature. So here also, we have three different variables. That is pressure, volume and temperature. Write down, these are the variables which, these are the variables which is used to define. Variables which is used to define the state of a system. Example, temperature, volume, pressure. Okay? What do you write? Pressure, volume and temperature. Okay? Write down, when all the state variable, when all the state variable is fixed, then we say that the system is at a particular state. The system is at a particular state. Okay? So at one state, we will have some pressure, volume and temperature. P1, P1 and P1 can change into P2, P2. So all the path or the method by which we can change any one of the state variable. We can have more than one change also possible. But if any one of the state variable is changing by which way, that way we call it as what? Process. Okay? So we have different, different process. Isothermal, you must have heard. Right? Isothermal process is what? Temperature constant. Isobaric. Pressure constant. Isocoric. Volume constant. Adiabatic. There is no exchange of which. So all these are processes. By these processes, we can change any one of the or more than one state variable. Okay? So the way or the path by which any one of the state variable changes, those path, they call it as different, different processes. Okay? So we will come to this process later. Next point you write down. There is various thermodynamic properties. Write down next. Thermodynamic properties. Two types of thermodynamic properties we have. One which depends upon mass and one which does not depend upon mass. Okay? So first property, we call it as intensive property which is independent of mass. Write down. Intensive property. These are the properties which are independent of mass. Does not depend upon mass. Independent of mass and it is non-arritable. Independent of mass and non-arritable. Non-arritable. We cannot add this. Okay? Example you write down. This example is important. Next question on which one of these is intensive or extensive property. We cannot add. Suppose density. Density is intensive or extensive. Tell me. Intensive. Intensive. Sir, it is not independent of mass. Okay. Intensive. If you add more of the system density. Density is what? Intensive. Intensive property because it is independent of mass. Right? One glass of water you take or one bucket of water. The density of water won't change. Okay? So density is an intensive property. Okay? So density of, suppose water you are taking and oil. So you cannot, if you mix these two, we cannot add, if they ask you what is the density of the mixture. You cannot add both density of water and oil. That's what it is non-arritable. Right? So write down the example here. Density. Temperature. Pressure. Concentration. Density. Temperature. Pressure. Concentration. Concentration. Concentration term means what? Molarity. Molarity. Mole fraction. All these are intensive property. Okay? Density. Temperature. Pressure. Concentration. Boiling point. Melting point. Right? Molar heat capacity. What is molar heat capacity? Per unit mole, if you calculate. Molar heat capacity and then specific heat capacity. Specific heat capacity. And specific volume also in intensive property. Weber pressure is also intensive. Specific volume. Volume of unit gram or unit mass of a substance. Say specific term means we are talking about unit mass. Molar term means we are talking about unit mole. So whenever specific and molar term is written, that term is what? That term is intensive property. Because we are talking about one mole or one gram. Okay? Weber pressure write down next. And also intensive property. Okay? It's important. Next write down extensive property. Depend on mass. Extensive property. It is additive in nature. Extensive property, additive in nature. Example write down. Example write down mass, mole. Energy means internal energy, enthalpy, Gibbs free energy and entropy. Everything. Internal energy, enthalpy, Gibbs free energy, Entropy. All these are extensive property. Resistance, entropy. Entropy. What is the name of this chapter? Yes. Do you know about entropy? No? Yes. Handle this. Handle this. I am not talking about this. Okay? Entropy. Resistance, heat capacity. Heat capacity is also extensive. Right? So this thing you must take care of. Heat capacity is extensive. But molar heat capacity is what? Intensive. Special heat capacity is intensive. Because we are talking about one mole or one gram. Okay? So this you must take care of. Next write down. One note you write down here. The ratio of two extensive property. The ratio of two extensive property. Will be an intensive property. The ratio of two extensive property. Will be an intensive property. For example you see. Molarity. Right? Molarity. How? Molarity is intensive or extensive? Intensive. Intensive, right? And it is equals to what? Mole divided by? Volume. Volume. Volume. Correct? So mole is what? Intensive or extensive? Extensive. This is extensive? Yeah, extensive. Volume is what? Extensive. Extensive. So ratio of two extensive property is intensive. Right? Similarly density also you can see. Density is equals to what? Mass by volume. Mass by volume. Mass is extensive. Volume is extensive. And density is what? Intensive. Intensive. So ratio of two extensive property is always intensive. Just remember that. Okay? So if you do not know some term formula you know you can identify the formula you can write and check whether it is the ratio of two extensive property or not. Okay? Make sure I write down. Thermodynamic function. Thermodynamic function. Thermodynamic function. Thermodynamic function. Then you have to see. But like for any example if you see. What we can do? Any more than two examples? Yes. Suppose if you look at the product connection you will see what is possible. Number of moles into molecular mass it is extensive. This is also extensive. So suppose you will have term like this. Suppose P divided by Q into R and so on. So what is the product? Yeah. If it is plus minus then extensive or intensive you can write. If more than two term you have either you will have multiply here or multiply. So when you multiply or divide, multiply like this then the property won't change. Number of moles into molecular mass is the mass of the substance. Extensive, extensive, extensive. But when you take the ratio the property changes. So with that you may have the idea. But suppose if this is extensive, this is extensive. So this whole term will be extensive. And if it is extensive then this whole term will be intensive. No it is mass so it is an extensive property. Anyways next we write on thermodynamic function. Thermodynamic function again we have two types. Thermodynamic function. Two types of thermodynamic function we have. The first one is state function. And the second one is path function. State function write down. These are the term which depends upon. Term which depends upon initial and final state only. Which depends upon the initial and final state only. And independent of the path followed. State function. Depends upon the initial and final state only. For example pressure, temperature, internal energy, enthalpy, Gibbs free energy, entropy, volume. All these are state functions. Point of this is what you see. Suppose at this we are considering two points A and B. At this point we have certain pressure, volume and temperature. And at this point we have certain pressure, volume and temperature. By any process if this comes over here. There are many paths possible. One is this, another one is this, another one is this. Right. Infinite path possibilities. Use internal energy. Internal energy, enthalpy, Gibbs free energy and entropy, volume. Okay. So when you are at this point, no matter what path you are following. The pressure will be P2 only. Volume will be V2 only. Temperature will be P2 only. So this is a state function. It depends upon initial and final state. Not on the path followed to gain this state. Right. Like for example if I talk about work. Right. Work done. Or heat. It is a state function or path function. Path function. Because the amount of work you are doing depends upon what path you are following. Correct. So this path is, you can see it is the smallest path we have. So amount of work is what? Less. When you follow this path, when you go through this path. You have to do more work. Right. So work done is what? Work done is a path function. Energy term is a path function. Okay. No, no, no. We are talking about work done and energy involved. Path function will be energy and work done. For example of path function. That is what I am saying. So second function will write down. Second function will write down. Write down these are the terms. These are the terms. Which depends upon. These are the terms. Which depends upon. Path followed. Or the path function. For example, heat and work. Heat and work. Energy and work.