Questions tagged [hydrogen-bond]

Bond between covalently bound hydrogen atom and atom possessing a lone pair of electrons.

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29
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2answers
25k views

What exactly is hydrogen bonding (and does it really need fluorine, oxygen, or nitrogen)?

I'm not satisfied with the rationale for the intermolecular attraction known as hydrogen bonding. In my book, it states that Hydrogen bonding is a special type of intermolecular attraction between ...
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3answers
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Is hydrogen bonding generally defined to include only three period two elements?

Traditionally, hydrogen bonding has been defined to only include interactions between a positively polarized hydrogen and three period-two elements: nitrogen, oxygen, and fluorine. Why was this ...
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Why is HCl not considered to have hydrogen bonding?

A molecule that has hydrogen bonding usually follows these two premises. 1.) There is a hydrogen atom involved 2.) Hydrogen must be bonded to a highly electronegative element which are ...
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1answer
11k views

How does intramolecular hydrogen bonding cause the molecules to be separated from each other?

I learnt about intramolecular hydrogen bonding today, which occurs between molecules such as ortho-nitrophenol. What I was told is that in case of intramolecular bonding, the molecules separate from ...
19
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2answers
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Why is the boiling point of stibane higher than that of ammonia?

I recently came across the fact that the boiling point of $\ce{SbH3}$ (stibane) is greater than that of $\ce{NH3}$ (ammonia). I was expecting $\ce{NH3}$ to have a greater boiling point as a ...
13
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4answers
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Why can't alcohols form hydrogen-bonded dimers like carboxylic acids?

Carboxylic acids such as acetic acid are capable of forming dimers: I'm wondering why alcohols like ethanol don't generally form dimers. In the diagram below, the oxygen atom on the left ethanol ...
5
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2answers
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Strength of intramolecular vs intermolecular hydrogen bonds

Why are intramolecular hydrogen bonds weaker than intermolecular hydrogen bonds?
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2answers
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Is Hydrogen Bonding a Type of Dipole Dipole Interaction?

I understand that dipole dipole forces is due to the attraction of the different partials charges of atoms in different molecules due to their different electro-negativities. For hydrogen bonding, ...
38
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4answers
952 views

Do symmetric hydrogen bonds in neutral molecules exist?

As far as I know, there have only few truly symmetric hydrogen bonds been observed. Unquestionable is the existence of it in the bifluoride ion, $\ce{[F-H-F]-}$, see also here. There are a couple of ...
10
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1answer
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Why does hydrogen bonding in salicylic acid make it more acidic?

When salicylic acid deprotonates (losing the proton from the carboxyl group) it forms a hydrogen bond with between the oxygen in the carboxylate anion and the hydrogen in the alcohol group. However, ...
14
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2answers
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Can an amide nitrogen be a hydrogen bond acceptor?

Can $\ce{N}$ (i.e. main chain $\ce{NH}$s of recognised residues in a peptide or protein) be a hydrogen bond acceptor? It is a well known fact that the main chain $\ce{NH}$s can be a hydrogen bond ...
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5answers
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Why does hydrogen fluoride have a boiling point so much lower than that of water?

$\ce{F}$ has more unshared electron pairs and is very electronegative, so $\ce{H}$ of another $\ce{HF}$ molecule can $\ce{H}$-bond with it. $\ce{HF}$ has normal boiling point of $\pu{19.5^oC}$ while $...
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3answers
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Does deuterium exhibit hydrogen bonding?

I searched for this on Google but I only got research articles in the SERP. I know of the concept of hydrogen bonds, that they are a special class of van der Waals forces between highly ...
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1answer
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Relative strengths of hydrogen bonds

Order of hydrogen bond strength: $\ce{O-H...N}$ > $\ce{O-H...O}$ > $\ce{N-H...N}$ > $\ce{N-H...O}$. Why is that so? According to me $\ce{O-H...O}$ should have the maximum strength while $\...
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1answer
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Are there any other elements that get less dense in their solid state?

I was learning about how water, because of its hydrogen bonds, actually gets less dense as it goes into its solid state - I was just wondering, what other elements do this? Are they similar to water? ...
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How does a water molecule bond to an anhydrous salt to form a hydrate?

Some sites suggest that water molecules bong to anhydrous salt via a "loose bond". What does that even mean? $\ce{H2O}$ is a polar molecule and salts are made up of ionic bonds. Is it a hydrogen bond ...
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1answer
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What is a hydrogen bond?

I was doing a little research on the Chemistry of water, and it said that water molecules have a hydrogen bond between them. What is it, and what does it do to water?
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1answer
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In which state does the bifluoride anion exist?

Statement 1. The $\ce{HF2-}$ ions exist in solid state and also in liquid state but not in aqueous state. Statement 2. The magnitude of hydrogen bonding between $\ce{HF}$ is weaker than that ...
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2answers
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Does oxygen gas form hydrogen bonds?

I learned that hydrogen bonding is formed from a 'sandwich' of hydrogen and either oxygen, nitrogen, or fluorine where nitrogen, fluorine, or oxygen is the bread. Will oxygen gas and water form ...
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2answers
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Which intermolecular interaction is dependent on the inverse cube of distance?

The intermolecular interaction that is dependent on the inverse cube of distance between molecules is: hydrogen bond ion-ion interaction ion-dipole interaction London force Inverse ...
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1answer
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Why is the boiling point of water and ammonia so different?

Boiling point of water is 100 degrees Celsius, while boiling point of ammonia is minus 33 degrees Celsius, which makes 133 degrees difference. Now when we discuss value of boiling point, we also say ...
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4answers
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Is the strength of hydrogen bonding greater in hydrogen peroxide or water?

When we compare water and hydrogen peroxide's hydrogen bond strength, which one should have the greater one? I know that peroxide has more hydrogen bonds, but when we compare the strength of each ...
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3answers
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Is there intramolecular hydrogen bonding in salicylaldehyde?

Is there intramolecular hydrogen bonding between the hydroxyl and carbonyl groups? I think personally is that it does but what is concerning me is that I have got no adequate answer or response to my ...
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1answer
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What are the prerequisites in hydrogen bonding?

I know when a hydrogen bond is, but - can hydrogen bonds only occur between two molecules containing hydrogen? Or, only one of the molecules should contain hydrogen and the other one may not contain ...
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2answers
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How many hydrogen bonds in these compounds?

We usually get some questions about how many hydrogen bonds these compounds can create, we use it to differentiate between the boiling point of each one of them so it would be great if you could help ...
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1answer
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Why is density of water maximum at 4 degree celsius?

Why is density of water maximum at 4 degree celsius? We were having a discussion to this question in class and I could gather the following points. 1) $H_2O$ exists in a cage like structure in ice ...
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2answers
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Why alcohol is volatile although it has hydrogen bonds?

We are always told that hydrogen bonds increase the boiling point of a liquid and as a result they decrease the liquid's volatility. I want to know the reason why, alcohol with hydrogen bonds is ...
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1answer
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Is a hydrogen bond considered to be a van der Waals force?

Is a hydrogen bond considered to be a Van der Waals force?
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2answers
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Water and Ice - density

We know that ice has a lower density than water despite both having the same [molecular] mass. I know that as water turns to ice, it expands. As far as I was taught, I know that it has something to do ...
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3answers
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Why is ice less dense than water?

I know the traditional explanation, which says that ice has large spaces between $\ce{H2O}$ molecules because hydrogen-bonding gives it an open structure. But what does the open structure have to do ...
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1answer
127 views

Why is hydrogen bonding more significant than any other interaction between dipoles?

Solvents can be categorized as polar and protic. I understand that to be protic there had to be a significantly polar bond involving a hydrogen atom. However, how is the a hydrogen bond different in ...
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1answer
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Dichloromethane solubility in water

I heard dichloromethane is soluble in water 1:50, but I also heard it is not because it can't form hydrogen bonds. I'm confused. Is there a way to extract it? Would putting the water to $40~\mathrm{^\...
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1answer
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Which are stronger intermolecular forces: ionic bonds or hydrogen bonds? [closed]

Do strong ionically attracted molecules have stronger intermolecular forces than hydrogen bonding forces?
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1answer
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Intermolecular forces between carbon dioxide and water

I'm wondering which intermolecular forces will exist between carbon dioxide and water. Instinctively, I would expect there to be only dispersion forces between the 2 molecules, because carbon dioxide ...
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2answers
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Structure of the bifluoride anion [duplicate]

I came across this structure of $\ce{HF2-}$ and realized that the bond shown between H and F is a hydrogen bond. $$\Large\ce{[F-H-F]-}$$ HF hydrogen bond are the strongest hydrogen bonds we know, ...