😳Complete Chemistry in ONE Video? All Formulas for NEET 2026 | Wassim Bhat

Added: 2026-05-04

[00:00:00]So my dear students, this particular session is going to be the complete chemistry formula revision. It's going to be a very short and precise session, right? And this particular session will help you in order to memorize all the formulas which are involved in all the chapters of your chemistry and you know in your neat examination there are I mean more than like four to five questions right from your physical chemistry part which are directly the formula based ones. So if you remember the formula then only you can solve those questions. If you do not remember those formula you cannot solve those question. First of all let's start with the mole concept. In the mole concept how many ways do we have to calculate number of moles? You know there are three ways by means of which we can calculate number of moles of a particular substance. The first formula is given mass of the substance in grams divide by molar mass of the substance.

[00:00:52]Given number of particles of the substance divide by Aadro's number that again gives me the moles given volume of the gas at STP divided by 22.4 4 L. This is one more result by means of which we can calculate number of moles of a gas which will be present at STP. Right? And if the condition is not STP, then we will have to use the ideal gas equation with the help of which you can calculate moles of the gas. N is equal PV / RT. P stands for pressure of the gas. V stands for volume of the gas. T stands for temperature of the gas. Right?

[00:01:27]Moving ahead. My dear students, there is one mole conversion diagram which you need to know. In order to calculate number of moles, either I should be given with mass of substance or I should be given with volume of the substance, I mean volume of the gas or I should be given with the number of particles.

[00:01:47]Right? You know given mass of the substance divide by molar mass that gives me moles or number of moles of the substance multiplied by molar mass of the substance that gives me the mass.

[00:01:58]Similarly, given number of particles divide by Aadro's number that gives me moles. Moles multiplied by Aadro's number that again gives me number of particles. Similarly, given volume of the gas in L divided by 22.4 L that gives me moles. Moles multiplied by 22.4 L that gives me the volume of the gas.

[00:02:17]So with the help of this particular diagram you can do some basic basic equations in which uh in which you can convert mass into volume into particles particles into mass etc etc right similarly my dear students over here imagine that you have got two chemically non-reacting gases in the container this is gas one and this is gas two I'm assuming that these gases are chemically non-reacting if these gases are chemically ally non-reacting that means these gases won't react to form any product. So these are non-reacting gases right? So basically I have got a gaseous mixture present in the container.

[00:03:00]Perfect. I've got a gaseous mixture present in the container. Now my dear students let me tell you the mass of one mole of a gaseous mixture. You call that as average molar mass of the mixture.

[00:03:12]Right? And how do you calculate that average molar mass of the mixture? That is mass of the mixture in grams divide by total moles present in the mixture.

[00:03:21]This is one result. Similarly, m1 ns1 + m2 n2 divid by n1 + n2. What is this n1 n_sub_2? n1 n_sub_2 represents moles of each components over here. And m1 m2 represents the molar masses of these gases. Right? Similarly, there is one more result with the help of which you can calculate the average molar mass that is molar mass of gas one multiplied by mole fraction of gas one plus molar mass of gas 2 multiplied by mole fraction of gas 2. Similarly my dear students if this mixture will be present at constant pressure and temperature at that point of time this is the result with the help of which you can calculate the average molar mass of the mixture.

[00:03:58]So these are different ways with the help of which you can calculate average molar mass of the gaseous mixture.

[00:04:04]Right? Then comes your vapor density.

[00:04:07]How do you define vapor density of a particular gas? Vapor density of the gas is defined as density of the gas divided by density of hydrogen gas. Provided the gas and hydrogen they are kept at same pressure and temperature. In the similar way molar mass of the gas is equal to 2 * the vapor density of the gas. There are some questions in the empirical molecular formula wherein you'll be having you'll be using this particular result. Now similarly if you apply this particular result to a gaseous mixture containing non-reacting gases. Do remember vapor density of the gaseous mixture is always equal average molar mass of the mixture divided by two. This is one more result which you are going to remember over here. Okay. Going ahead.

[00:04:52]Percentage of an element in a given compound is equal molar mass of the element multiplied by number of moles number of moles of the atoms. number of the moles of the atoms of the element in one mole of the compound divided by molar mass of the compound multiplied by 100. One simple result with the help of which you can calculate the percentage of an element in a given compound. In the similar way, percentage yield is always equal experimental amount divided by expected amount multiplied by 100.

[00:05:24]Percentage purity of a compound in an impure sample. It's always equal mass of pure compound in the impure sample divided by mass of impure sample multiplied by 100. Right? All these topics I've taught you in detail in this particular channel only. Right? Moving ahead. Molecular formula and empirical formula. This is the result. Molecular formula is equal to empirical formula multiplied by N. What is N? N does not represent the moles. And it represents the ratio of molecular mass of the substance to that of empirical mass of the substance. Right? Now comes to the concentration terms. You know with the help of this one you represent solvent.

[00:06:01]With the help of this two you represent solute. W stands for mass. N stands for moles. E stands for equivalent mass.

[00:06:07]Right? Now weight by weight percentage of solute is always equal mass of solute in grams divided by mass of solution in g multiplied by 100. weight by volume percentage of solute is equal mass of solute in grams divided by volume of solution in ml multiplied by 100.

[00:06:24]Similarly, volume by volume percentage of solute is always equal volume of solute in ml divided by volume of solution in ml multiplied by 100. These are some basic results. Dear students, there are few more results which you need to know. Weight by volume percentage of solute that's always equal weight by weight percentage of solute multiplied by density of solution in g per ml. Right? Mole fraction of solute is equal moles of solute divid by total moles present in the solution. Mole fraction of solvent is equal moles of solvent divided by total moles present in the solution. In case of the binary solution k1 plus k2 it's always equal to one. When it comes to the marity, number of moles of solute divided by volume of solution in liters or mass of solute in grams multiplied by th00and molar mass of solute volume of solution in ml.

[00:07:14]Similarly, marity is equal 10 * density of solution. Weight by weight percentage of solute divide by molar mass of solute. One more result. Marity of the solution is called 10 * weight by volume percentage of solute divide by molar mass of solute. One more result to calculate marity comes to the mality.

[00:07:31]mality number of moles of solute divide by mass of solvent in kg or mass of solute in grams multiplied by th00and divide by molar mass of solute multiplied by mass of solvent in g right there is one more result which connects mity with marity directly marity is equal * marity divided by 1,000 * density of solution minus marity multiplied by molar mass of solute in the similar way mity is equal mole fraction of solute multiplied by,000 divided by 1 minus mole fraction of solute and this is molar mass of solvent. So these are some important results right from which directly formula based questions can be asked. I believe it's clear. Coming to the chapter or there is one more dilution formula you know it m1 v1 is equal m2 v2 or mixing formula marity of the resulting solution is equal to m1 v1 plus m2 v2 divided by v1 plus v2 when you have got non-reacting solutions.

[00:08:28]Okay. Now coming to the atomic structure. In the atomic structure if I ask you what is the energy carried by one photon? It's H new or HC by lambda.

[00:08:37]What is the energy carried by n photons?

[00:08:40]It's n * h new or n * hc by lambda. What is the combined value of h and c? It's 1 to40 electron volt angstroms. At that point of time you will take lambda and angstroms. H multiplied by c value you can take as 1 to 4 electron volt nanometer. At that point of time lambda has to be taken in nanometer right and at the same time you know 1 electron volt is nothing but 1.6 6 into 10^ -19 Jew. Okay. How do you calculate power of the source? It is energy emitted divide by time taken. Energy emitted will be NHC by lambda and divide by time. This n / t over here is something which you call as the rate of emission of photons.

[00:09:20]Rate of emission of photons. Now comes to the Einstein's photoelectric equation. Incident energy is equal to work function plus kindinetic energy maximum of the photo electron. Right?

[00:09:31]Incident energy you can write is H new is equal to H new plus K max or instead of H new you can write HC by lambda this will be HC by lambda this is K max or you can write the same equation in terms of stopping potential as well you can write instant energy is equal to work function plus EV KN where V not here is not the threshold frequency V not is the stopping potential here right similarly there are questions directly based on the formulas based on the BS model radius of the nth B's orbit Right? This is how you compare the radius of two Bor's orbits. Velocity of the electron in the nth B's orbit. This is how you compare the velocities of two electrons going in two different Bor's orbits. Time period of electron. And this is how you compare the time period of two electrons. Perfect. By the way, n over here represents the shell number in which electron moves and zed represents the atomic number of that single electron specy which we are talking about. Total energy puzzles by the electron is equal -3.6 z² by n square electron volt. Kinetic energies plus of this potential energy is - 27.2 z² by n². Maximum number of spectral lines obtained when the electron makes a transition between two between two energy states. That's n_sub_2 - n1 multiplied by n_sub_2 - n1 + 1 divid by 2 where n_sub_2 is the higher energy state. N1 is the lower energy state. How do you calculate the wavelength of the electromagnetic radiation which gets emitted or absorbed when the electron makes a transition between two energy states? 1 by lambda is equal to rz² 1 upon n1 square - 1 upon n2 squ where n1 is the lower energy state. N_sub_2 is the higher energy state. And let me tell you 1 / r value do remember it from now onwards it's 911.5 angstros right perfect. Similarly moving ahead the broad wavelength lambda is equal h upon p right or p you can write as mv or you can write p in terms of kinetic energy under root of 2 m kinetic energy or if you have got the charged particle q which is accelerated at a potential difference of v how do you calculate this de wavelength lambda is equal to h upon under root of 2 mqv and particularly for an electron lambda is equal 12.27 divid by under root of v.

[00:11:50]This result is for electron. When the electron is accelerated at the potential difference of V. Okay. In case of Heisenberg's uncertainty principle, error in position multiplied by error in momentum, it has to be greater or equal to H upon 4 pi. Or you can say delta X dot delta V is greater or equal H upon 4 pi M. Okay. Similarly, how do we calculate the total number of nodes? N minus one. How do we calculate angular nodes? The value of L as a middle quantum number. Radial nodes L n minus L minus one. Right? Orbital angular momentum under root of l into l + 1 h upon 2 pi. What is l? l here represents what? It represents the estimal quantum number. Total number of subshells in a given shell is equal to the value of n.

[00:12:31]n is the principal quantum number.

[00:12:33]Number of orbitals which maximum orbitals which will be present in a particular shell. That's equal to n².

[00:12:39]Similarly, maximum number of electrons that can be accommodated in a particular shell that's equal to n². Right?

[00:12:45]Perfect. At the same time guys, I'll be sharing the PDF of this particular session in my telegram and telegram is uh chemistry by vasims chemistry by w ss i m s right on that particular telegram channel. I'll be sharing the PDF of this particular session. Okay. All right.

[00:13:03]Then comes your thermodynamics. In thermodynamics, how do you calculate work? Work is equal to minus integral v_sub1 to v_sub_2 external dv. Now we have got two processes. One is reversible, one is irreversible. In case of reversible processes, external pressure and pressure of gas they are almost equal. Therefore, this is the formula with the help of which you calculate the work done in case of reversible processes. And this is the formula with the help of which you calculate work done in irreversible processes minus P external delta V. Now there are a lot of questions in which you are supposed to calculate the amount of heat absorbed or released by the system and there are many ways by means of which you can calculate heat absorbed or released by the system. Number one, Q is equal to C delta T where is the C is the heat capacity, right, of the system.

[00:13:46]Q is equal MS delta T where S is the specific heat capacity of the system. Q is equal N cm delta T where cm is the molar heat capacity of the system right now at constant volume. This is how you calculate heat absorbed or released at constant volume. This is how you calculate heat absorbed or released by the system at constant pressure. Right?

[00:14:05]This is valid at constant volume. This is valid at constant pressure. Right?

[00:14:10]Now how do we calculate delta U for an ideal gas? Right? Delta U is equal N CV delta T. Delta H is equal N CP delta T.

[00:14:18]What is the relation between delta S delta U? Delta H is called delta U plus delta of PV. At constant pressure, you use this particular result. Keeping constant volume, you use this particular result. If pressure as well as volume both will be changing. This is the result. For a particular reaction which is carried out at a particular temperature, delta H is equal delta U plus delta NGRT.

[00:14:39]Right? Similarly in case of isothermal processes temperature of the system is constant right and if the ideal gas under goes isothermal process it has to follow this equation P1 V1 is equal to P2 V2. If the ideal gas under goes isoric process volume constant then it has to follow this particular equation.

[00:14:56]If the ideal gas under goes isobaric process right it has to follow this particular equation. And similarly in case of cyclic processes change in the value of a state function that's always zero. Therefore, delta U, delta H, delta G, they are all zero when it comes to the cyclic processes. I mean delta U net, delta H net, etc., etc. Moving ahead, as per first law of thermodynamics, you should know deltaU is equal to Q plus W. Heat absorbed or released by the system at constant volume is always equal delta U, right?

[00:15:23]And that deltaU is equal NCV delta T.

[00:15:25]Similarly, at constant pressure, it's equal NCP delta T. A lot of questions are asked in which certain reactions are carried out in an open vessel. How do you calculate work done in them? W is equal minus delta NG RT. What is delta NG? Number of moles of gaseous products minus number of moles of gaseous reactants. Similarly, CP minus CV is equal R for 1 mole of ideal gas. CP minus CV is equal NR for N moles of ideal gas. Gamma poisons ratio is equal CP by CV which is always greater than one. And CV is equal RID gamma minus 1.

[00:15:56]If you have got a mixture of chemically non-reacting gases, how do we calculate CV as well as CP for that mixture? This is the result. N1 CV1 plus N2 CV2 divided by N1 plus N2. Same goes for this one, right? CP mixture.

[00:16:10]Now you have got two types of isothermal processes. Reversible isothermal processes, irreversible isothermal processes. These are the results with the help of which you calculate work done in reversible isothermal and these are the formulas with the help of which you can calculate work done in case of irreversible isothermal. Now again you have got two types of adabatic processes and these are the three results with the help of which you can calculate work done in reversible adabatic and these are the two results with the help of which you can calculate work done in irreversible adabatic processes. One more type of question you would have seen that is how do we calculate the final temperature of the system? How do we calculate final temperature of the ideal gas which underos either reversible adabatic or irreversible adabatic? When the ideal gas under goes the reversible adabatic process, this is the result with the help of which you calculate final temperature of the gas.

[00:17:02]This is the result with the help of which you calculate final temperature of the gas. When the gas when the same ideal gas under goes irreversible adabatic process, this is the result with the help of which you calculate final temperature T2 of the gas. Right?

[00:17:15]When it comes to entropy, how do you calculate entropy change in mathematical definition is integral of dq reversible upon t. But a question is not asked as per this particular formula. Question is asked as per this particular formula.

[00:17:28]When the ideal gas when the ideal gas under goes under goes a thermodynamic process. How do we calculate entropy change of that ideal gas? This is the result or this is the result which you can use. Right? Similarly, delta G is equal delta H minus D delta S. If entropy is the sole criteria of spontaneity, then for the process to be spontaneous, delta S total has to be greater than zero. That means delta S system plus delta S surrounding has to be greater than zero. If delta S total is less than zero, non-spontaneous. If Gibbs free energy is the criteria for spontaneity at that point of time, I can say delta G for the system at constant pressure and temperature it has to be negative then only the process will be spontaneous. Similarly, if delta G for the system at constant pressure and temperature is greater than zero, we say the process non-spontaneous. I believe it's again clear to every one of you.

[00:18:18]Now when it comes to the important results of equilibrium, first of all, how do you uh if this is the reaction which is given to me which is at equilibrium. This is how you write the KC expression. This is how you write the KP expression where these terms are concentrations of reactants products at equilibrium raised by their stoometric coefficients. KP expression will be uh this is the expression where these are the partial pressures of reactant products raised by their own stoometric coefficients. Now the point is what is the relation between KP KC? You should know it now. KP is equal KC RT raised per delta L. Right? Similarly, how do you calculate equilibrium constant? It is equal rate constant of forward reaction divided by rate constant of backward reaction. Now imagine this is a uh imagine this is a weak electrolyte.

[00:19:06]Imagine this is a weak electrolyte. How do you calculate ionization constant of the weak electrolyte? Right? Which underos a dissertion like this. It is C alpha squid 1 - alpha. And if alpha is less than 0.05, this is the way by means of which you can calculate alpha at that time. Right? Now if that weak electrolyte is your weak acid or a weak base then ki is something which you call as Ka. Over here KI is something which you call as KB. If your weak electrolyte is either weak acid or weak base then in in case of weak acid KI is K. In case of weak base KI is KB. And these are the expressions with the help of which you can calculate KI. And if alpha for them is less than 0.05 05 then this is the way with the help of which you can calculate alpha as well right similarly when you talk about pure water pure water is also considered as a veilite right and here KW ionic product of water is nothing but concentration of H positive multiplied by concentration of O negative and at 25° centigrade it is 10^ minus4 therefore your result comes PH plus P is equal to 14 that is valid at 25° centigrade now if you have to calculate pH of any solution what you need need to do you need to calculate the total H positive ion concentration in the solution take minus log of that you'll be getting the pH of that solution if somehow you are supposed to calculate P of the solution what you are supposed to calculate get the O negative concentration of the solution take minus log of that get the P that's all right now when it comes to salt hydrarolysis you have got different types of salts salt of weak acid strong base salt of strong acid weak base salt of weak acid weak base right these are the three different types of salts which we First thing how do you calculate hydrarolysis constant? Hydraysis constant for different types of salts are given to us. How do you calculate degree of hydrarolysis? These are the results with the help of which you can calculate degree of hydrarolysis of different types of salts as given over here. And these are the formulas with the help of which you can calculate pH over here.

[00:21:02]Right? So any question from these formulas can come. Okay. Now in case of acidic buffer, how do you calculate pH?

[00:21:10]PH is equal pKa plus log of concentration of conjugate base divided by acid or you can directly say concentration of salt divided by acid.

[00:21:17]Similarly, in case of basic buffer, this is the result with the help of which you can calculate P. Perfect. And similarly, whenever you have got a sparingly soluble salt, how do you calculate it solubility product? This is the way. If the solubility here is s concentration of a y pos will be x * s. This will be y * s and k sp solubility product will be concentration of a y positive raised^ x multiplied by concentration of bx negative raised^ y. This is the general expression with the help of which we calculate the solubility product. Right?

[00:21:47]Now comes to your electrochemistry only few results we have. First thing you know for an element standard oxidation potential of an element is equal to minus times its standard reduction potential. Right? How do we calculate standard AMF of the cell? E not cell is called E not cathode minus E not anode.

[00:22:01]Where E not cathode as well as E not anode. These are the SRP values of cathode and anode. Now this is the nus equation which we use in the most of the questions. E cell is equal E not cellus 0.0591 divid by N log of QC. Delta G for the cell is equal minus NF cell. Delta G not for the cell is equal minus NF cell.

[00:22:21]When the cell is at equilibrium, this is the result which we use when the cell is at equilibrium. Now as per Faraday's first law mass of substance deposited or liberated at an electrode is equal to equivalent mass of the same substance multiplied by I T divided by 96500. What is I? The current which goes into the solution. T the time duration in which current enters into the solution divided by 96500. How do we get the moles of the substance deposed or liberated? I multiplied by T divide by N factor of the same substance which is being deposed or liberated. Multiplied what?

[00:22:52]96500 as per Faraday's second law.

[00:22:54]Right? What happens when you have got two or more than two electrolytic cells connected in series containing different electrolytes. Gram equivalence deposited or liberated at every electrode will be the same. Right? Now there are few terminologies which are related to conductance. One is your resistance.

[00:23:09]Right? Resistance is what? Row L by A.

[00:23:12]Its units are ohm. When it comes to conductance, conductance is one by resistance. Right? You call it as its unit will be simon. Conductivity 1 by R into L by A where L by is called as cell constant. You know it. And the units of conductivity here will be simon cm inverse. Molar conductivity is equal kapa multiplied by,000 by marity. If you are supposed to calculate it in s cm squared per mole equivalent conductivity kapa multiplied with,000 by normality 7 cm square per equivalent. Degree of dissociation degree of dissociation of the weak electrolyte is equal molar conductivity of the weak electrolyte at a given concentration divide by molar conductivity of the same weak electrolyte at infinite dilution. So these were few results which are related to your water to your electrochemistry.

[00:23:57]Now if you talk about your chemical kinetics if you got a balanced chemical equation how do you calculate rate of disappearance of reactant minus change in the concentration of reactant by time taken. Rate of appearance of product plus change in the concentration of product divided by time taken. How do you write the rate exactly? It is rate with respect to a will be minus 1 by stoometric coefficient change in the concentration of a divided by dt.

[00:24:20]Similarly in terms of B in terms of C in terms of C in terms of D it is just the difference lies in the sign over here.

[00:24:26]When you calculate rate with with the help of reactant you have to start with minus sign. When you calculate rate with the uh from the product you will be starting with the plus sign. That's all right. Similarly when you when it comes to rate law how do you write rate law for this particular reaction? It's a balance it's in balanced form. Rate is equal to rate constant concentration of a raised^ X concentration of B raised^ Y. How do you calculate XY? X and Y you calculate experimentally. X and Y you calculate experimentally. X is what you call as order with respect to A. Y is what you call as order with respect to B. And X + Y over here is something which you call as the overall order of the reaction. In case of zero order reaction, this is how you write the rate law. This is how you write the integrity rate equation. A is equal A minus KT.

[00:25:11]Half life in case of zero order reaction A by 2K. Degree of dissociation in case of zero order reaction. A by a KN completion time in case of zero order reaction is equal to A / K. Again when it comes to the first order reaction this how you write the rate law and these are the different formats of the integrate rate equations in case of the first order kinetics. You need to remember all of them. I have taught this in detail in the sessions if you remember. Perfect. Similarly halfife in case of first order is 0.693 by K.

[00:25:40]Completion time is infinite. That means a first order reaction never under goes 100% completion. Alpha is equal to 1 minus E^ minus KT. Time taken to complete X% of the reaction. Similarly, time taken to complete 75% of the reaction. Time taken to complete 87.5% of the reaction. Time taken to complete 99% of the first order reaction. All these are important which with the help of which you can solve questions in very lesser time. Then rate constant is equal a e^ minus c a rt your arinus equation and these are different formats of your arinus equation. Perfect. Right. Now this is one more result. This is one more result which you need to know. When you change the temperature of the reaction, how many times the rate of reaction change? Perfect. And your equation over here becomes R2 / R1 is equal to 2^ delta T which is change in temperature by 10. Perfect. Now comes the last thing. What is that? That is the solution chapter. In the solution chapter, the first formula comes from the R's law. Right? Partial vapor pressure. Partial vapor pressure is directly proportional to mole fraction.

[00:26:44]Mole fraction mole fraction in the solution phase. Perfect. Similarly, PB is equal to P not B KB. When you will be mixing to volatile liquids, this is how you'll be calculating total vapor pressure of that particular solution which is which has formed when you have mixed volatile liquids. When it comes to your L I mean relative to lowering in vapor pressure P A minus PS by P A is equal to K B. This is one more result which you can use over here to solve the questions. Your elevation involving point delta TB is equal to KB multiplied by marity where KB is what you call as molar elevation constant whose value is RT²id,000 LV where LV over here is the latent heat of vaporization and T is something which you call as boiling point of solvent.

[00:27:27]Here depression in freezing point is equal to KF multiplied by M. Pi your osmotic pressure is nothing but CRT where C is the concentration or marity of the solution. Right? Similarly, how do you calculate the vanoff factor, right? For that electrolyte which under goes dissociation. This is the formula 1 + n minus 1 alpha. How do you calculate vanov factor? For this electrolyte which under goes association 1 + 1 by n - 1 alpha. And for a non-elerite, what is the value of alpha? Alpha value is one.

[00:27:55]So these are the only formulas from which the questions will be asked.

[00:27:59]Nothing else. So please and please do remember them. Do remember them. Right?

[00:28:05]I'm telling you four to five questions will be directly formula based. If you remember these formulas, you can solve those questions. If you do not remember these formulas, you're done. Okay. So, with this, I'll be taking a leave. Take care. God bless you all and love you all guys. Bye-bye.