 The question is write down. I'll write down the question here. Try to solve this question question is blood freezes at freezes at 272 0.44 Kelvin and a solution of solution of 3 gram of urea in 250 gram of water water freezes at freezes at to 272.63 Kelvin calculate the osmotic pressure pressure at 300 Kelvin the density of blood is given D of blood means the density of blood is 1 gram per ml at 300 Kelvin Solve this question guys, and then we'll start the next part in it Try to solve this question Okay, I'll tell you what you need to do here. See osmotic pressure. We have to find out correct Osmotic pressure that is pi and pi is equals to CRT R value, you know, right T is given that is 300 Kelvin C. You need to find out concentration Right, so concentration you find out From the formula of because blood freezes the freezing temperature is given So Delta TF formula you use and find out molality, right? Find out molality that will be the concentration and then you find out pi So first of all what you do you just find out the concentration. Okay, and then we'll see tell me what is the concentration you are getting Anyone what is the concentration term? What is the concentration you are getting here? Anyone what is the concentration you are getting? Let me know guys. No guys whether you are getting or not. Otherwise I'll solve this Okay, I'm solving this wait wait. I'm solving this see in this question The blood freezes at two seventy two point four four Kelvin at a solution of Three gram of urea in two fifty gram of water. Correct. So Delta TF So Delta TF is equals to Kf into M Okay, kf into M and Kf is also not given in this question. Okay, fine. Kf is also not given in this question Okay, so first of all you see the molality is what M is equals to the number of moles Which is three gram of urea divided by the molecular mass of urea is 60 the whole thing is divided by okay It's given divided by the mass of water, which is 250 gram into thousand this gives you the molality Okay, and Delta TF is given here, which is 2.72 Okay, fine this molality will find out Delta TF is what? Blood freezes at this solution of three gram of urea freezes at this. Okay? Okay So freezing point of blood is given and the solution Freezes at this. Okay. So water is the solvent here Right water is the solvent and it's a freezing point is zero-degree Celsius, which is nothing but 273 Kelvin, so if I write down here TF is equals to zero-degree Celsius the freezing point of water, which is equals to 273 Kelvin and TF dash It is given in the question, which is 272 TF dash is given in the question, which is 272.63 272.63 Kelvin the freezing point of the solution is this now Delta TF is what? TF minus TF dash That is nothing but 273 minus 272.63 Which is 0.37 Kelvin? This is Delta TF Now with this Delta TF and molality will find out KF first. So KF is equals to what? KF is equals to Delta TF is 0.37 and molality is 3000 into 250 into 260. So when you solve this the KF value will get around 1.85. This is the value of KF Okay, with this value of KF now when the freezing point because the blood freezes at this point, okay, and The water freezing point is 273 Kelvin. So if the freezing point is this 272.44 Right, so for that case in what we can have the Delta TF is equals to again 273 273 minus 272.44 Okay, so when you subtract this you'll get 0.56 is the Delta TF Kelvin or degrees Celsius Okay, so this is the temperature difference we have when the blood freezes at this point and water at this correct This will is also equals to KF into M KF value. We already have at this temperature So molality will find out and that molality will be 0.56 Divided by the KF is 1.85 1.85 Okay, so this is Approximately equals to 0.303 now the concentration we have already. So C pi is equals to C R T C is nothing but 0.303 R is 0.082 and The temperature is given it is at 300 Kelvin. We need to find out Okay, so temperature is 300 so when you solve this you'll get 7.45 Or six atmospheric approximately understood this Let me know guys first Understood so this molality is The molality of blood Because osmotic pressure of blood we need to find out so we need to find out the concentration of blood and for Concentration of blood we need kf because tf is there tf dash is there right kf We need to find out so kf will find out from this Formula so you'll find out kf substitute here find out molality of blood and then pi is equals to CRT We have to use got it Okay, next write down see we have discussed about the Collegative property now We are going to discuss about the colligative property when the solution when the solute is electrolyte Okay, when the solute is electrolyte so Right down next write down next abnormal colligative property abnormal Collegative property You see this abnormal colligative property is nothing but same. We don't have Much difference into that Okay, but the only difference is this property we use when the solute is electrolyte Solute is electrolyte. There is nothing much to understand here Right, right. So what happens? You see if the solutes are electrolyte like suppose. I am using this NaCl NaCl Solute I am using so when you when you put this NaCl into Uh any solvent what happens NaCl dissociates into its ions Right, so NaCl suppose if you place in any solvent it converts into Na plus NaCl minus Okay, so Na plus and Cl minus see the number of ions in the solution increases now You have given NaCl it becomes Na plus and Cl minus So the number of ions increases and and the colligative property are those properties Which depends upon the number of particles Right depends upon the number of particles Correct. So when the number of particles increases in the solution Why because the solute is electrolyte then the colligative property also changes here Right, so that's why this kind of property you will calculate or find out the property according to NaCl Because you have added only one particle into it But in the solution it becomes Na plus and Cl minus. Okay, so number of particles increases Right number of particles increases. That is why That is why the colligative property That we expect we are not getting the same colligative property here Right, so colligative property also changes a bit That's why these kind of properties when the solute is electrolyte. We are calling it as abnormal colligative property Okay, so for this Right, so this formula formula is exactly same that we did but to counter this this abnormal behavior We use a term and that we call it as abnormal that we call it as went-off factor Okay, so write down into this Write down See what you have to keep in mind You have to you have to understand this that the solute that you are using whether it is electrolyte or non-electrolyte like I said urea Glucose sucrose and sucrose These are non-electrolyte These are non-electrolyte Okay, these are non-electrolyte And this does not dissociates. Okay, but n a c l like so this you have to keep in mind. Okay, sometimes in the question Sometimes in the question, they'll give you they'll mention Okay, they'll mention that We use In the solution of electrolyte non-electrolyte solute or electrolyte solute like this it is mentioned But sometimes when these kind of solutes they use you should keep this in mind that these solutes are Non-electrolyte solutes and these solutes are electrolyte solute Okay So the point is in case of abnormal colligative property. What is the term that we have to introduce? Okay, so first of all you write down here If the solute particles dissociates or associates if the solute particles Dissociates or associates Dissociates or associates in both the cases Because in both cases the number of particle changes dissociates or associates upon dilution upon dilution Then upon dilution, then there will be then there will be A deviation deviation from the expected The expected colligative property expected colligative properties And these properties are called these properties are called Abnormal colligative properties Abnormal Collegative Properties Right abnormal colligative properties this deviation from the expected value This deviation Write down this deviations Is measured by deviation measured by measured by a term called Went-off factor went-off Factor Which is represented by i Okay more value of i more will be the deviation more i went-off factor more will be the Deviation Got it copy it down guys Yes fractures also it is a non-electrolyte