Skip to main content
Ch.11 - Liquids & Phase Changes

Chapter 11, Problem 50

When ethyl alcohol, CH3CH2OH, dissolves in water, how many hydrogen bonds are formed between one ethyl alcohol molecule and surrounding water molecules? Sketch the hydro- gen bonding interactions. (Hint: Add lone pairs of electrons to the structure before drawing hydrogen bonds.)

Verified Solution
Video duration:
3m
This video solution was recommended by our tutors as helpful for the problem above.
1148
views
Was this helpful?

Video transcript

Hello. Everyone in this video we're talking about methanol and properly molecules and we're seeing how the interactions of hydrant bonding works here. So we go ahead and schedule those hydrogen bonding interactions and we are given a hit in this problem that before drawing any hydrant bonds will have to go ahead and add the lone pairs on our auction atoms. So first let's go ahead and drop the structure for methanol. So methanol has our method group as well as our alcohol group. So we have the prefix of meth meaning we have just one carbon and then our suffix of O. So O. L. And that's just because we have an alcohol group. So then we have our methyl group here. So H three C connected to an auction and hydrogen that's our alcohol. And because auction likes to have two bonds and two lone pairs we already have the two bonds. So adding those two lone pairs. That's methanol here now for propranolol. So we have the prefix of probe that's going to mean that we have three carbon. So we have H three C. Ch two ch here, those three carbons and our alcohol groups of H. Again we have two bonds. So adding the necessary two lone pairs. So as we call the hydrant bonding means that we're dealing with are hydrogen atoms bonding between a very electro negative atom such as nitrogen often and flooring. So when it has those bonds that's what we call a hydrogen bonding. So we said earlier that there's going to be too long pairs on the oxygen atom of propranolol. And because of that it means that the molecules can go ahead and set to bonds just from those two lone pairs. We all see for O. H. That we have a hydrogen bond to our auction. So because we see that O. H bond there's going to be a total of three pro bono molecules that can form. So now start shooting out our interactions because we already dropped the lone pairs on each of our molecules here, we'll go ahead and do this in green. So starting off with our proposal, we have H three C CH two, CH 2 and then our oxygen and hydrogen of course with our long pairs here now for the methanol groups, I go ahead to create this interaction. We'll do we'll do it in blue and as well as showing the hydrogen bonding interactions with a dotted blue line. So the auction is going to form a bond with our hydrogen of our methanol and then we'll have comparison oxygen and the methyl group. Same thing with the lone pair in the bottom this dotted line with our hygiene and then we'll have our auction number two lone pairs and another bond to our method group. Now for the auction instead of dealing with another hygiene were being bonded with the auction now so then we'll have our dash line here with the auction and its lone pair, two lone pairs. And then we have our methyl group and the other end being a hydrogen. So let's see here that we have had made three interactions total.
Related Practice
Textbook Question
Mercury has mp = -38.8 °C and bp = 356.6 °C. What,if any, phase changes take place under the following condi-tions at 1.0 atm pressure? (a) The temperature of a sample is raised from -30 °C to 365 °C.
821
views
Textbook Question
How much energy in kilojoules is needed to heat 5.00 g of ice from -11.0 °C to °30.0 °C? The heat of fusion of water is 6.01 kJ>mol, and the m# olar heat capacity is 36.01 kJ>mol for ice and 75.4 J/K mol2 for liquid water
1014
views
Textbook Question
How much energy in kilojoules is released when 25.0 g of ethanol vapor at 93.0 °C is cooled to -11.0 °C? Ethanol has mp = -114.1 °C, bp = 78.3 °C, ΔHvap = 38.56 kJ>mol, and ΔHfusio#n = 4.93 kJ>mol. The molar heat#capacity is 112.3 J>1K mol2 for the liquid and 65.6 J>1K vapor.
1332
views
1
comments
Textbook Question
Water at room temperature is placed in a flask connected by rubber tubing to a vacuum pump, and the pump is turned on. After several minutes, the volume of the water has decreased, and what remains has turned to ice. Explain
366
views
Textbook Question
Benzene has a melting point of 5.53 °C and a boiling point of 80.09 °C at atmospheric pressure. Its density is0.8787 g>cm3 when liquid and 0.899 g>cm3 when solid; it has Tc = 289.01 °C, Pc = 48.34 atm, Tt = 5.52 °C, and Pt = 0.0473 atm. Starting from a point at 200 K and 66.5 atm, trace the following path on a phase diagram. (1) First, increase T to 585 K while keeping P constant. (2) Next, decrease P to 38.5 atm while keeping T constant. (3) Then, decrease T to 278.66 K while keeping P constant. (4) Finally, decrease P to 0.0025 atm while keeping T constant. What is your starting phase, and what is your final phase?
2486
views
Textbook Question
Intermolecular forces are important in creating ordered arrangements in liquid crystals. What types of intermolecu- lar forces exist in a sample of the following compound?

410
views