AB Sir Electrochemistry part 7

本站添加: 2026-05-18

[00:00:00]now the next application of quadrature is that we can find the solubility of a sparingly soluble salt and third application is that we can find the degree of dissociation of the vehicle equate see when we say about the weak ligament suppose if I ask you you tell me how that is what is the degree of dissociation of acetic acid what do you say it is so cspp what we say with associates Philby but if I say what is the degree of dissociation of Excel you say yes it dissociates to a large extent around 99 percent associates you're given some value can give some value for the we click let's know what we say the word but I said II what do you say it dissociates fee fee which is how much 20 percent 30 percent 15% 16% 17% how much there is some value today now is right so feeble you cannot be some value should be there so previously before kollross we may not know any formula by which we can calculate the degree of dissociation of the big net match do you not know any form that the degree of dissolution of Italy of course in also my direction law you studied in class 11 we study those for dilation law the degree of dissociation but there are certain limitations there in those twelve direction all right there are certain limitations I'm not going to those limitations now you know you've studied in chemical equilibrium but here you do not have any such limitations we can calculate the degree of dissociation of any vehicle a to it like magnesium chloride barium chloride acetic acid barium sulfate silver right what against a chloride in this way any vehicle applied we can a degree of association but it now because previously used to just simply say theoretically it is so chic sweep it is so she gets to a small extent but how much there should be some value what is the right how to calculate a degree of dissociation now we can calculate well help us for Russia what is the formula I find is equal to alpha is the degree of decision of e cleared one alpha is equal to taxi and by cap infinity and C means concentration mix melodic conductivity any given concentration let us say I have given you barium chloride I've given you barium chloride event and the concentration of barium chloride is 0.01 molar so what you see here C is here 0.01 molar the see this is nothing but zero point zero Vanilla Ice Arena taxi and beam SWAT it is simply campaign also eternity down there is no difference recapping and calcium cm writing specifically because it is a molar and activity of the human concentration so what is the concentration let us say 0.01 Beulah so at is zero point zero and Maura what is the molar conductivity which will be given to you and molar conductivity and infinite dilution will graphs be given me you know the formula how just noise Eddie Jack cm by nu plus lambda plus plus nu minus lambda minus just now my sorry once you know of this values you put it here and you will divide it you will be getting the degree of dissociation now what is the degree of dissociation you get it it is in fraction you have to multiply in two hundred percent to get a percentage because you know degree of dissociation Association is calculated in terms of percentage degree of Association of dissociation is calculated in terms of percentages in this the degree of dissociation in terms of percentage for a week electro lunch okay now next after that very sorry another that is application is that we can calculate the solubility of the sparingly soluble salt see sparingly soluble salt for example you know silver chloride when you add it to water it dissolves it market the very smallest means if you take one liter of water and if you take just a pinch or one less than that also if you take a pinch less than that a pinch in water if you put it you'll find it will be solid or you can find also that some part of it also will be insoluble okay but I said you take one liter water and you add silver chloride to it a pinch of silver to read out of that also you see something with meaning line it will not dissolve that means what inform say but saturated solution is it because the saturated solution solution which which cannot dissolve any more the saloon in also it is not ready to dissolve for that reason only something is done behind now are you able to understand or not here what I handed a pink chalk to it I invited to one liter of water out of that little bit remains undissolved that means what reforms a saturated solution because saturated solution is solution which cannot dissolve any more the solute at a given temperature it cannot dissolve then only some things will be made and moreover the solution which I got it the satchel solution which I got it it is also solution at infinite dilution how because what I sell you one liter water or more than that also heated and a pinch of salt at taking it which made is less than a gram we can span it can do a less than a gram so it is not an infinitely dilute solution because water is sOooo large compared to that of the solute the solvent is so large compared to that of the solute all right then only as infinitely time have you understood I say at this point because you need to understand the concept first then only you'll be able to understand the formula from wherever giving it because I said you IDs sparingly soluble solid so I have two silver chloride you can take any sparingly soluble salt for barium chloride silver chloride magnesium chloride baby what it can say this sulfate or it calcium sulfate any sparingly soluble salts pairing it once and that it dissolves in water very very very very small extent negligible amount that is what I said but it's a year example I gave it to you that you take a pinch out of that when you add a pinch of salt to the water you see how got that still a little bit the remains are dissolved that means what is saturated solution and how much water you've taken one liter or loaded that water you have taken and salt a pinch so it is is it not infinitely Guyot solution yes so this solution which I got it it is not only infinitely dilute but also it is a saturated solution I got it but which kind of salt sparingly soluble salt Oh fine I hope you understood the concept now here I need to calculate the Sun in it all right I need to calculate the solubility so here that is tapa that is salt is equal to what will I have negative tapa saturated solution minus Kappa water in everything from a saturated solution if you remove water that you are going to get it so it enough isn't it just now you said you know you want a GCM you take a saturated solution of HCl and remove the water from it then what is what is remaining but it remains missile only it repeats so understood the formula first that Papa salt is equal to Kappa solution - water will give you what the basalt finished first now next is cap em is you studied captain the color yeah can be civil towards the Kaaba a study that is molar conductivity what is study Papa in 2000 by and you study now here captain is not captain here it is molar conductivity finite Luc just now I said you the solution which you be taking of silver chloride it will be infinitely dilute this is a 1 liter water or 2 liter water and you are adding a pinch of sorts it is an infinitely direct sense I can say instead of captain I can't write tack infinity then now Cap'n mm by n n is what here every solubility here M is your solubility of the salt sub you believe D off the side why because solubility is it is measured in molarity M is also measured in polite but it is also visiting Milan see in this way here Kappa is 1 here what I can say Kappa is nothing but Thomas or you write it or not taka simply unity desktop a salt that is clear so it stands for your solubility so what I need here I want to measure the solubility of spending is on your side I want em which is solubility here so but what is the found I'll get the salt in 2000 by cap infinity and cap infinity M you can break it up nu plus lambda plus plus nu minus lambda X this wooden simplified but it Kappa salt you will get it in this way you will put the ready you will get the N n is what I said solubility of the salt because solubility is also measured in terms of molarity is mole's per liter and molarity is also measured in terms of all spider instead of m this'll be finished in this way you can calculate the solubility of sparingly soluble salt yeah we can get ya now what about if the solubility is arsing gram per liter sorry if it is accent instead of moles per liter is actually grams per liter what do you need to do to convert moles per liter to gram per liter what you need to you need to multiply the molecular weight whatever I said you get it man yeah and you multiply it molecular weight you will be converted you will be getting in grams per liter why because see very simple molarity is varied by molecular weight into volume in liters that is molarity formula so gram per liter disease evaporator see here it is measuring gram and qualities in liter so I wonder answer W 1 by V so what I need to do I need to multiply molar it into molecular weight so hence I said that if the question is asked if the question is actually beginning the sort of numericals that it calculate the solubility in gram per liter don't leave the answer in words per liter converting it to gram per liter how do you do so multiplying Entomology Alexia a min to a month so I will multiply the molecular weight to convert it into ground polluted all right now molecule at my molecular weight of the soil it's not minor your molecular weight molecular rate of the salt you multiply it you will get that answer solubility of the soil 10 gram per liter or if it is actually molds political debate as it is the answer all right so in this way these are applications of cauldros thank you