Propanol (PrOH) and methyl methacrylate (MMA) asso-ciate in solution by an intermolecular force, forming an adduct represented as PrOH•MMA. The equilibrium con- stant for the association reaction is Kc = 0.701 at 298 K. (b) Draw a plausible structure for the PrOH • MMA adduct. Use to signify an intermolecular interaction.

Video transcript

Hello everyone today. We have the following problem. The association of acetone and ethanol in a solution forms an AD acct by an inter molecular force that is represented by ethanol, acetone. The association reaction has an equilibrium constant of 0.781 at 67 kelvin. What is the possible structure for the addict? So as you may have guessed an AD accT is simply the result of an addition reaction. So two molecules coming together to form one essentially We need to find out what these two molecules looks like. 1st. So first we're gonna draw the lewiS structure for our acetone. Acetone has three carbons, six hydrogen and one oxygen carbon is a group for a element and therefore has four valence electrons, Hydrogen is the group one a elements. So it has one valence electron And oxygen is a group six a element and it has six valence electrons. However, we must note That there are differing amounts of these elements. So we have three carbons and six hydrogen. And so when we add up the total number of electrons, We get 24 electrons to construct our diagram. And so since carbon is a group for a element, it can form four bonds, oxygen can form into two bonds and hydrogen can form into one bond. So acetone is going to essentially end up looking like this and notice how we have accounted for all of our electrons as well as our atoms. Next we have to draw the lewis structure for ethanol, Ethanol has two carbons, 6 hydrogen and one oxygen so far carbons as you said before is a group for a element. So it has four valence electrons, there's two of them. So we have eight total electrons, hydrogen as we stated before as a group one a elements. So it has one valence electron. However there's six. So we have six total electrons for hydrogen And then oxygen is a group six a element. So it has six valence electrons and there's only one. So When we add up the number of electrons that we have, we get a total number of 20 electrons to construct our diagram. The same principles are going to apply and ethanol is essentially going to look as such. We're going to have a method attached to a carbon and that carbon is going to be attached to a hydroxyl group or an O. H. Group. And then that second carbon is also going to be bonded to two hydrogen. And so we have to see how these would come together. So in an addict reaction we have a hydrogen donor and a hydrogen except er. So for our hydrogen donor this is essentially going to be a very electro negative adam such as flooring, oxygen or nitrogen. Our hydrogen except er on the other hand, is going to be an electro negative atom on a nearby ion or molecule that has a lone pair. So generally has a lone pair. And so in this case in this situation here, our donor, our hydrogen donor would be our acetone and our hydrogen, except er would be our ethanol. And so when we draw our ad acct, so down here draw our adducts. It is essentially going to be our ethanol, providing that hydrogen so that the hydrogen can bond with this electro negative oxygen. And so we're gonna draw that attached to the acetone there and that's going to be present as such. And if you look at our answer choices, answer choice B best reflects our diagram. And with that we've answered our question overall, I hope this helped, and until next time.