Hydrogen bonding Definition and 30 Threads

Summary: doesn't this decrease entropy ? Cellulose is known for its hydrophilic quality, which can be explained from the polarity of its hydroxyl groups. We all know water can overcome the force of gravity through a piece of paper you put in the water. Correct me if I'm wrong but this is a...

I can't figure out why hydrogen is more likely to bond to either the nitrogen or to the sulphur atom. I can't locate any information in any textbooks or online as to which molecule is more prevalent/common. This is not a homework question. I just came across one of these molecules and wondered...

if the human skin consists of hydrogen, then why does not happen hydrogen bond through contact with something or with another person?

Homework Statement How many hydrogen bonds can methyl 2-hydroxybenzoate form with molecules of the same compind? Homework Equations N/A The Attempt at a Solution There's a hydroxyl group on the second carbon of the benzene ring and a double-bonded oxygen with 2(3?) lone pairs, so I'm...

I took about 100 ml of distilled water, put a small, clean rock in it (to prevent "bumping" or explosion) and heated it repeatedly in a microwave oven on high for 45 seconds. After each heating I checked the temperature of the water with a digital temperature probe. I did this 7 or 8 times...

Induced dipoles result in Van der Waals' forces and permanent dipoles in hydrogen bonds, right? But how do you know is a compound has formed hydrogen bonds or Van der Waals' forces? For example, HF forms hydrogen bonds while HCl forms Van der Waals' forces and not hydrogen bonds. But in HCl, H...

Homework Statement The problem was to tell how many hydrogen bonds there are between cytosine and guanine. and I know there are three. http://study.com/cimages/multimages/16/Cytosine_Guanine_base_pair.png But I think I might be misunderstanding the hydrogen bond concept. I thought that hydrogen...

Effect of intermolecular hydrogen bonding is as follows I don't understand one point i.e how occurrence of liquid state is associated with intermolecular hydrogen bonding as intermolecular hydrogen bonding helps in closed packing of molecules it should give rise to solid state.

Homework Statement In a DNA molecule, the base pair adenine and thymine is held together by two hydrogen bonds (see figure below). Let's model one of these hydrogen bonds as four point charges arranged along a straight line. Using the information in the figure below, calculate the...

For those of you who know what a Hansen Solubility Parameter is, does the "hydrogen-bonding" part means the actual hydrogen bond energy between molecules? I'm confused as to why they used mPa^0.5 instead of kJ/mol^-1 for measurement.

More acidity means more electronegativity, and more electronegativity means more dipole moments. I observed that liquids with low dipole moments (bases) often have lower density and surface tension, but not necessarily hydrogen bonds. To contradict it, acetic acid have a low surface tension but...

How do you strengthen and weaken hydrogen bonds in water aside from changing its temperature? Could you add any solutes to do so?

If you draw lewis structure, central atom (N) will have 1 lone pair and 4 single bonds with Hydrogen. Why can't hydrogen in this ion molecule be able to form hydrogen bonding with other molecules alike? Is it because there's only 1 electron on the central atom?See for yourself: 5N + 4H -1 = 9...

< Moderator Note -- thread moved to Homework Help forums > Shouldn't Propylamine (C3H7NH2) be able to form hydrogen bonds with alike molecules? Hexane (c6h14) doesn't seem to have hydrogen bonding capability.

What is the relationship between polarity and hydrogen bonding? I have come across several problems saying that an alcohol is more polar than a ketone because of hydrogen bonding but I don't see the relationship between these two. Intuitively, I thought ketone would be more polar because it has...

Intermolecular hydrogen bonding is stronger than intramolecular hydrogen bonding. But how to differentiate between an intermolecular and an intramolecular hydrogen bonding ? How can I know if there is the presence of an intermolecular or an intramolecular hydrogen bonding in a molecule ?

Hey, How do you know how many hydrogen bonds ethanol molecules will form with each other? I know there are 3 sites where H bonds could form (2 lone pairs on oxygen and the hydrogen) but with something like hydrogen fluoride, each molecule only forms 1 H bond on average so shouldn't something...

Homework Statement I have attached a solution to one of my homework questions that states "Draw hydrogen bonds that might be formed between a water molecule and the following compounds: a) H3PO4; b) PO43-; c) aniline; d) pyridine; e) ethylamine; f) ethyl ammonium ion; g) acetic acid." My...

Does chlorine make a hydrogen bond? I was doing a practice problem in my book and the question was regarding the intermolecular forces, and the compound had chlorine and it said no, but my professor said it does. Which is true?

Homework Statement is significant hydorgen bonding possible in phosphine, PH3 The Attempt at a Solution The text says no, I don't see why not. P has 5 electrons in its outer shells, 3 of those form an ionic bond with the 3 H. That leaves 2 non-binding electrons, those 2 non-binding...

Homework Statement Which of the following substances exhibits significant hydrogen bonding in the liquid state? A) CH_{2}F_{2} B) N_{2}H_{4} C) CH_{3}OCH_{3} D) C_{2}H_{4} E) C_{2}H_{2} Homework Equations The Attempt at a Solution I know that hydrogen bonding generally only works...

Sorry to butt in on your form. Please can someone help me with this – I’m sure it’s simple to those who know but I have been thinking about these 2 problems for ages (and reading up on every website I can find) and still no answer. I am trying to get a basic understanding of this and seem to...

Every water molecule is H-bonded with up to four other molecules (two through its two lone pairs, and two through its two hydrogen atoms. These 4 intermolecular hydrogen bonds are what contribute to water's high boiling point.. My textbook compares this with Fluorine, which it says can...

Rank the following base pairs according to their stability. Rank from most to least stable. To rank items as equivalent, overlap them. ------------- I have found out that the first one is thymine-adenine pair and the second one is a cytosine-guanine pair. The third one is cytosine...

Anyone aware of the Physics of Hydrogen Bonding ?? Please suggest resources ! Hi everyone, Am a grad student doing experimental research in an interdisciplinary lab of nanoscience - I am using the concept of hydrogen bonding in some of my experiments. I am planning to...

Homework Statement The following structures illustrate hydrogen bonding interactions between amino acid side chains and/or backbone atoms within a protein structure. In which of the following figures are the structures and hydrogen bonding completely correct? Homework Equations...

hydrogen bonding with NH3 please.help.ASAP! Homework Statement NH3 is a donor & acceptor of hydrogen in hydrogen bond formation...Draw a diagram to show the H bonding of an ammonia molecule w/2 other NH3 molecule. Homework Equations The Attempt at a Solution this is waht i...

[SOLVED] Hydrogen bonding Which types of bonding are present in CH3CHO(=ethanal) in the liquid state? I. Single covalent bonding II. Double covalent bonding III. Hydrogen bonding A. I and II only B. I and III only C. II and III only D. I, II and III The solution is A but I can not...

I was wondering why hydrogen bonding only occurs in molecules containing H and one or more of the following: N, O, and F. Why isn't Cl included in this list? The reason I ask is because the electronegativity of Cl is very close to (and even equal to one of) the electronegativities of the...

Hi, i have more of a chemistry than a physics question. I am conducting an experiment to separate ethanol from water via fractional distillation, however through calculations i have found that some of the ethanol remains bonded to the water due to the strong hydrogen bonds. Is there any other...