Ethanol 1CH CH OH 2 dissolves in hexane 1C H 2. Give the strongest type of intermolecular force between two sol- ute molecules, between two solvent molecules, and between a solute and solvent molecule. (LO 13.1) (a)

Video transcript

Hello everyone today. We have been given the following problem. What is the dominant inter molecular forces present between solvent molecules between solute molecules and between a solute and a solvent molecule. When propane all is dissolved in di ethyl either. So the first thing we want to recall, the different types of inter molecular forces and inter molecular forces just refers to forces that are between molecules. Inter means between and molecular refers to molecules. So there's three main inter molecular forces. There's hydrogen bonding or h bonding. And this is when a hydrogen is bonded to an electro negative atom such as flooring, oxygen or nitrogen. We then have what's known as di pole die pole bonding And this occurs between two polar covalin molecules, two Polar covalin molecules. And lastly we have what's known as London dispersion forces and these are actually going to be your weakest types of inter molecular forces. They exist in every molecule and they mostly reside in non polar molecules. So now that we have those established as our base, it's time to establish what is our solute and solvent. So our salute in this problem is going to be professional and why is that? It's because propane all is being dissolved into something. So remember a salute is dissolved in something while a solvent. So solvents dissolve. That's the main difference. So I saw you is propane all whereas our solvent is going to be our di lethal either Next we want to draw out our structures. So we want to recognize that propranolol is going to appear as one methyl group which is a carbon bonded to three hydrogen as it's drawn out we have a methyl bonded to a carbon That has two hydrogen and then that carbon is bonded to another carbon that has two hydrogen is on it. And then lastly that last carbon is bonded to an oxygen and a hydrogen or an O. H. Group. And so next we have to determine the inter molecular force. Well, according to our periodic trends, oxygen is more electro negative than both hydrogen and carbon. So we're going to draw our diet paul moment arrow towards oxygen. So from hydrogen to the oxygen and from the carbon to the oxygen. And we notice that this oxygen has an immense amount of electron density. So what we are going to say for propane all is we're going to say that propane all. Not only does it have a net dipole moment, but it is exhibiting di pole di pole forces, right as we defined it. We have a polar we have polar forces happening here. We have this O. H. Group and we have this ceo group. We can then also look at a secondary instrument of force which is hydrogen bonding because as we stated before, hydrogen bonding is when you have a hydrogen bonded to an election negative atom such as fluorine, oxygen or nitrogen. And so to answer the salute salute interaction right, our saw us probe and also we have 22 proposals together they're going to actually form hydrogen bonding and that's because hydrogen bonding is of course stronger than our dipole dipole. So that takes precedence. So for our saw you saw its hydrogen bonding that gets rid of answer choices two and 3. Moving on we look at solvent solvent interactions and that's going to be our diet di ethyl either and based on the structure provided by this and either is an oxygen that is bonded on both sides by carbon groups. And so we have one carbon on the right one carbon on the left. The carbon on both of these carbons are going to be bonded to two hydrogen. And then we're also going to have those carbons bonded to a methyl group and it's the same on the opposite side as well drawing out our diet paul moments we said that oxygen is more electoral negative than carbon. So we're drawing arrows in that direction as before We have a net dipole moment. So for di evil other we have dipole dipole interactions know that we do not have hydrogen bonding here and that is because there is no hydrogen bonded to an election negative adam. So for our solvent solvent type interaction, it is going to be predominantly die paul di pole answer choices one in four both have solvent solvent for a dipole dipole. So we move on to the last and final one. So if we were to react our soul ute with our solvent, what would we have? Well our salute, which is propane. All so you right over here we have propane. All Its strongest force is going to be that hydrogen bonding. And for our die heather its strongest is going to be that die pole di pole type interactions. And so this O. H. Group is going to want to bond with this oxygen group in a hydrogen bond, so therefore our solute solvent interactions are going to be hydrogen bonding. So this is going to be our answer here. And if you look at our answer choices, answer choice, a oriental choice. One has all of the correct answers overall, I hope that this helped. And until next time.