Questions tagged [hydrogen-bond]
Intermolecular force between covalently bound hydrogen atom and atom possessing a lone pair of electrons.
265
questions
0
votes
2
answers
2k
views
Why does hydrogen bonding require a lone pair? [closed]
Why does hydrogen bonding require a lone pair of electrons on the partially negative atom? They would still be partially negative even without the lone pair right? Or does a bond exist, but is much ...
3
votes
0
answers
86
views
Why ethyl cyanide and propanol have the same boiling point?
As I understand, the intermolecular forces of ethyl cyanide are of van der Waals nature (dipole-dipole) but in the propanol molecule there are hydrogen bonds which are in principle much stronger. Why ...
1
vote
0
answers
132
views
Hydrogen bonding in acetylene and other terminal alkynes
My textbook says that hydrogen bonding is possible only when there is acidic hydrogen connected to an electronegative atom like $\ce{N}$, $\ce{O}$ or $\ce{F}$ and a basic lone pair of electrons on ...
-1
votes
1
answer
890
views
Why is Bonding between H and Cl not considered as H bonding? [duplicate]
Cl is an electronegative element and hydrogen is electropositive. Why are intermolecular interactions involving H and Cl not considered as H bonding? I read it in a book but there was no reason given ...
0
votes
1
answer
118
views
Effect of isotopes on H-Bonding
The following question was asked in one of the assignments my teacher has given.
Acetone ($\ce{Me2CO^16}$) on treatment with $\ce{H2O^18}$ gives a mixture of $\ce{Me2CO^16}$ and $\ce{Me2CO^18}$, the
...
0
votes
1
answer
527
views
Compare the boiling points of isobutane and 1-butyne
Question: Compare between the boiling points of isobutane and 1-butyne
The answer to this question is given as 1-butyne has higher boiling point than isobutane.
My approach: I have been taught a few ...
2
votes
1
answer
1k
views
Relative strength of intermolecular forces [duplicate]
My attempt at a solution:
First I look for hydrogen bonds:
The only compounds with hydrogen bonds are the second and fourth ones, so they have the strongest intermolecular forces. The second must have ...
2
votes
1
answer
69
views
Hydrogen bonding in sugar acids
I recently learnt that the reason for low solubility of mucic acid as compared to glucaric acid was more hydrogen bonding in the crystal state of mucic acid as compared to glucaric acid.
I would ...
0
votes
0
answers
64
views
Why isn't there a hydrogen bond present between the oxygen atom and hydrogen atom of adjacent alcohol groups?
*I know that there is inter-molecular hydrogen bonding between the molecules of glycerol.
*What makes the adjacent alcohol groups behave differently towards each other as compared to when they ...
1
vote
1
answer
157
views
Why don't dicarboxylic acids show hydrogen bonding in spite of the fact that carboxylic acids exist usually as dimers in polar aprotic solvent? [closed]
I have seen several examples:
The fact that maleic acid is more soluble in water than fumaric acid in spite of the fact that it must be able to show intramolecular hydrogen bonding.
trans-...
2
votes
1
answer
377
views
What is exposed in the surface tension of water?
(I guess) I understand the covalent bonding of water and the hydrogen bonding of water between two different molecules, but I would like to know which part is the part that that exposes itself to the ...
1
vote
0
answers
208
views
Why aren't the hydrogen bonds in carboxyllic acids like this?
Why don't carboxylic acids form H-bonds in this formation with the red dots (diagonal) instead of the black dots (horizontal)?
I was always taught that H-bonds formed between partially negative and ...
1
vote
0
answers
125
views
Water solubility comparison of stereoisomers of bicyclo [4.4.0] decane-3,4-diol
I think, (I) must be more soluble in water. It is due to trans configuration and thus, forming more effectively inter-molecular hydrogen bonds with water molecules.
1
vote
0
answers
148
views
Factors dominating forces between acetone and chloroform
What type of interaction is present between acetone and chloroform?
According to me, acetone has weak hydrogen-bonds with chloroform, the hydrogen on an electronegative atom has electron density that ...
7
votes
2
answers
4k
views
Solubility of ortho- and para-nitrophenol in benzene
Which one between o-nitrophenol and p-nitrophenol is more soluble in benzene? And what is the reason? If the solvent had been polar, hydrogen bonding would have provided a lot of explanation, but what ...
-1
votes
2
answers
155
views
If acid releases proton then how can a proton react with another proton to form hydrogen gas? [duplicate]
As we know that acid releases proton (H+ ion) when dipped in water hydrogen has a proton and electron only . To form H+ hydrogen releases 1 electron and it becomes proton. But when Acid reacts with ...
3
votes
1
answer
2k
views
How does the entropic force arise within the hydrophobic effect?
I know that the hydrophobic effect is usually explained by the entropic effect originating from the disruption of hydrogen bonds between molecules of water and the nonpolar substance. The hydrogen ...
1
vote
0
answers
33
views
How to get the right formulas for combustion (rocket chamber) or where to find them? [closed]
I am a space enthusiast and am intrigued mostly by rockets.
I recently found a book HOW to DESIGN, BUILD and TEST SMALL LIQUID-FUEL ROCKET ENGINES and have been fiddling around with rocket engine ...
0
votes
0
answers
22
views
How the attraction takes place between a hydrogen atom and the acceptor atom in a hydrogen bond
In hydrogen bonds present in water,does the hydrogen atom attracts to the lone pair of electrons present on the oxygen atom or to its partial negative charge? If former is the case are there any ...
7
votes
2
answers
1k
views
Do amines or alcohols have stronger intermolecular hydrogen bonds?
Which has stronger hydrogen bonding, $\ce{CH3OH}$ or $\ce{CH3NH2}$
I think it comes down to which has more dominance; number of hydrogens, number of lone pairs, or electronegativity.
4
votes
0
answers
247
views
Extent of Hydrogen bonding in H2O2
Several books that I have read say that in $\ce{H2O2}$ the degree or extent of H-bonding is 6 as each H atom would form 1 and O atom would form 2 H-bonds respectively. However if we look at HF the no....
1
vote
0
answers
45
views
it is possible for the hydrogen bond to form between the hydrogen chloride molecule, HCl? [duplicate]
Recently I'm doing my work, and I can't find what it is the answer. Can you guys help me?
-2
votes
1
answer
48
views
Is a compound that reacts with another to form hydrogen for fueling aircraft possible [closed]
Hydrogen is the most abundant element in the universe and has great properties when reacting with oxygen for use as a fuel. Yet here on Earth, its production is prohibitively expensive, its storage ...
0
votes
1
answer
3k
views
Why do boiling points of alkanes and alcohols become closer with increased chain length
I came across this graph, which clearly shows a large difference between the boiling points of alkanes and their equivalent alcohols.
However, it is clear that as chain length increases, the ...
0
votes
0
answers
1k
views
Effect of intramolecular hydrogen bonding on the stability of a molecule
What will be the effects of intramolecular hydrogen bonding on the stability of a molecule? Will it increase or decrease the overall stability of a molecule? Or will it not have any impact on the ...
2
votes
4
answers
5k
views
Strength of Hydrogen Bond and Angle
This link has a short paragraph on the very first page, which says: "There are two useful criteria to evaluate the presence and the strength of a H-bond. The first is to look at the distance between ...
2
votes
0
answers
470
views
which oxygen atom make intramolecular hydrogen bond in salicyclic acid?
When I googled about intramolecular hydrogen bonding in Salicylic acid, I found that there are two type of hydrogen bonding. Which one is more appropriate?
And another question, if there ARE two ...
3
votes
0
answers
494
views
Why does Pubchem show cis-1,3-cyclohexanediol with the hydroxyls in the equatorial position?
I am a beginning organic chemistry student and trying to reason about something based on information in my book, but seeing that Pubchem gives a different structure than I'd expect.
In considering a ...
2
votes
0
answers
95
views
Hydrogen Bonding by Carbenes
A hydrogen bond is formed between hydrogen attached to highly electronegative atoms (nitrogen, oxygen, and fluorine) which are small in size too and the non-bonding pair of electrons of another such ...
1
vote
0
answers
127
views
Increase of peak intensity in case of hydrogen bonding
Typical motif in case of hydrogen bonds is charge transfer from electron rich acceptor Y to (usually) anti-bonding X-H σ* orbital. If so, the X-H bonding distance increases, bond weakens, stretching ...
0
votes
0
answers
464
views
Why does ammonia have higher melting point but lower boiling point than HF? [duplicate]
I guess the reason is hydrogen bonding, but shouldn't both the trends be similar in that case?
0
votes
2
answers
6k
views
Raman Spectrum of Water
This is the Raman spectrum of water. There is $\pu{1635 cm-1}$ Raman peak corresponding to $\ce{HOH}$ and $\pu{3410 cm-1}$ Raman peak corresponding to $\ce{OH}$. But why is there general nonzero ...
2
votes
1
answer
250
views
Hydrogen bonding of chlorine [duplicate]
Even though nitrogen is less electronegative than chlorine according to Pauling scale bit why don't it form hydrogen bonding as effective as of nitrogen ? ( Electronegativity valve of N =3.0,Cl=3.2)
4
votes
0
answers
845
views
Why mixing water with ethanol produces heat energy? [closed]
Sorry if I'm asking something stupid but I'm trying to understand where this energy gets from. As far as I could find, it is not a reaction as both chemicals left unchanged, so it might have something ...
0
votes
0
answers
39
views
Why does energy need to be "compensated" in order for solvation to occur?
I am currently learning about the physical properties of alcohols.
I understand that the main intermolecular forces between alcohols and water are hydrogen bonds. When these two are mixed, the ...
2
votes
1
answer
2k
views
Boiling point of ethanamide vs propanamide
I just have a question regarding the boiling points of some primary amides. Ethanamide has a boiling point of 222 °C, while propanamide has a lower boiling point of 213 °C. Both amides are capable of ...
6
votes
2
answers
12k
views
Why is dichloromethane immiscible in water?
We know that like dissolves like. And dichloromethane is a polar solvent and water is also a polar solvent. Also there ought to be a strong hydrogen bonding between the chlorine and hydrogen atoms. So ...
6
votes
0
answers
1k
views
Diazo Coupling reaction with para-substituted phenol?
Usually Diazo coupling occurs at para-position unless the para-position is occupied, in which case coupling occurs at ortho-position.
While solving questions I found in both the cases as shown, the ...
7
votes
0
answers
198
views
How does the accumulation of hydrogen bonds affect individual bond strength?
I saw the question, "Is the strength of hydrogen bonding greater in hydrogen peroxide or water?" and it made me think of a question on hydrogen bonding:
If an oxygen on a water has a ...
2
votes
0
answers
151
views
Hydrogen Bonding in Water (MO theory)
Valence Bond Theory tells us that each of the “sp3” (in reality, 44% s character) oxygen line pairs in water can act as electron donors, but observing the MO diagram for water tells us that the 2 non-...
1
vote
1
answer
579
views
Complementary base pairing
In the molecular structure of a DNA it is seen that purines (adenine and guanine) bind with pyrimidines (cytosine, uracil and thymine) through hydrogen bonds, and this is always between a purine and a ...
0
votes
1
answer
142
views
Why are hydrogen-bonded compounds (such as NH3) excellent solvents for most lab reagents? [closed]
Hydrogen bonds are said to be one of the strongest molecular interactions in nature. Then why can most substances that interact through hydrogen bondig such as water and $\ce{NH3}$ able to dissolve a ...
3
votes
1
answer
2k
views
Why HI isn't fully miscible with cold water when HF is?
HF is more soluble in water than HI, due to greater hydrogen bonding in HF, accepted, but on the other hand HF is a weak acid so it's dissociation will be meagre when compared to HI's dissociation, so ...
6
votes
1
answer
3k
views
Can =NH2+ in Arginine's side chain form hydrogen bonding at physiological pH?
I know that at physiological pH, Arginine will have its $\ce{=NH}$ protonated to $\ce{=NH2+}$. I was wondering if this $\ce{=NH2+}$ can still form a hydrogen bond by being a donor? And does the ...
0
votes
2
answers
496
views
What would be the intermolecular forces between the molecules of methanetetrol?
Methanetetrol has the following chemical formula: $\ce{CO4H4}$. It is also referred to as orthocarbonic acid.
Since the molecule has a molecular geometry of a tetrahedron, similar to that of a ...
-2
votes
1
answer
436
views
How hydrogen molecule is formed? [closed]
How two hydrogen atoms come close to form a bond ? Textbooks refer to a potential energy diagram but what i cant understand is what is this potential energy if the atoms are neutral . How they come ...
6
votes
1
answer
4k
views
What is the best hydrogen bond acceptor in 2-amino-N-(3-hydroxyphenyl)acetamide?
I was preparing for my first exam in organic chemistry and came across this question.
Draw a water molecule that is hydrogen bonded to the best anticipated hydrogen bond acceptor.
2-amino-N-(3-...
0
votes
1
answer
1k
views
Dimerisation of HOOC-COOH in non polar solvents
In a textbook I read, the following question is my doubt:
Why is the answer B)? Why do the other molecules not dimerise? How does it work?
(P.S- Why dosen't the B) option only form hydrogen bonds ...
2
votes
2
answers
4k
views
Stability of geometrical isomers in cycloalkanes
Among the following, which should be the most stable compound?
1)Cis-cyclohexane-1,2-diol
2)Trans-cyclohexane-1,2-diol
3)Cis-cyclohexane-1,3-diol
4)Trans-cyclohexane-1,3-diol
My thought process is-...
2
votes
2
answers
3k
views
Hydrogen bonds - why not in HCl? [duplicate]
In a textbook1, I found the following clear definition of hydrogen bonds:
The strongest secondary bonding type, the hydrogen bond, is a special case of polar molecule bonding. It occurs between ...