 One question you write down which is not based on this. Let's you write down this question two liquids a and b wait I'll write down the question here Two liquids a and b forms an ideal solution a and b forms an ideal solution What will be the vapor pressure? will be the vapor pressure at 27 degrees Celsius of Of a solution Having Number of moles of 8 is given 1.5 and number of moles of b it is given 4.5 Where pressure you need to find out P naught a is given 0.116 and p naught b is 0.140 respectively Oh, sorry a and b it's given already Done. What is the answer? Okay, see i'm doing this See the pressure we need to find out so pressure is what? P naught a P naught ax a plus p naught b x b Everything is given just need to find out the mole fraction So p naught a is 0.116 x a is 1.5 divided by total so 0.5 plus this it is 6 plus 0.140 Into 4.5 divided by 6 So the answer will be 0.134. Yeah 0.134 is correct Okay And one more question you write down A solution containing A solution containing containing 25.6 gram of sulfur gram of sulfur dissolve in dissolve in 1000 gram of naphthalene naphthalene whose melting point Is 80.1 degree celsius The depression in freezing point depression in freezing point is observed to be 0.68 degree celsius find out the formula of sulfur of sulfur Kf is given kf for naphthalene is 6.8 kelvin per mole in all cases, uh Shiram, we cannot say we have to see the number of moles if it is very less like we did that question Then we can take it depends upon the number of moles given Okay, and obviously the options also according to that you can take the approximation We cannot generalize this that always you can neglect Depends na and nb value What is 8? The question is the molecular formula, Shiram Sahana Yuta S8 Yeah, it's right See what we do We'll find out i value correct so delta tf Is equals to i kf into m Delta tf is given 0.68 i we do not know kf is given that is 6.8 and molality is what? 25.6 25.6 Divided by what the atomic mass of sulfur it is 32 And this whole divided by the mass of solvent is 1000 gram into 1000 So when you solve this you'll get i is equals to 1 by 8 i is equals to 1 by 8 Which means i is less than 1 which is the case of Association Case of association and this thing in the denominator This gives you initial number of Initial number of particles And this gives the number of particles after association which one This means what eight sulfur atoms combines and forms one molecule So that's why the molecular formula of sulfur is s8 that we get in the solution One last question you write down Among the following solutions which shows the lowest osmotic pressure I am writing down here few compounds You have to tell which one has lowest osmotic pressure 0.10 molar molar NaCl This is first one 0.05 molar CaCl2 Second one 0.04 molar K3 FeCN6 0.03 molar FeCl3 You need to tell which one has lowest Which one has lowest osmotic pressure? What is the answer? 0.03 molar FeCl3 FeCl3 why FeCl3 because it has lowest value right? See the only thing we need to check is the effective concentration because pi will write here The osmotic pressure pi is equals to ICRT Right ICRT why I because all are electrolyte this r and t won't change so IC For the one which has minimum value of IC Minimum i into c Gives you minimum osmotic pressure Right in some book they also write this product as c effective C effective into rt So minimum c effective minimum osmotic pressure. Okay, so for this one i value is what I'll write down here i value is 2 C is given i value is 3 here C is given i value is 4 And i value is 4 Okay, 3 plus 1 4 so 2 into 0.10 it gives you 0.20 c effective For this c effective will be 0.15 For this c effective will be 0.12 and for this c effective will be 0.16 so this one has Minimum value of c effective hence the minimum osmotic pressure Maximum osmotic pressure will be for k3 FeCl6 Understood Right, so this is it for this chapter guys. I'll send you some uh, did I share the assignment on this? I have shared it already. I guess Okay, solve those questions I will share the solution soon on this Okay, thank you guys. Thanks a lot for joining. Okay, do solve all those assignments that I have shared already Thanks all Bye. Bye. Good night