Questions tagged [hydrogen-bond]
Bond between covalently bound hydrogen atom and atom possessing a lone pair of electrons.
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Types of Bonds in Ethylene Glycol [closed]
I know that Ethylene Glycol contains hydrogen bonds. But I'm not sure whether it contains dipole-dipole forces because when I drew the structure, I noticed there were two COH bonds. I'm not sure ...
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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 ...
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1answer
80 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 ...
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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 ...
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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 ...
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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.
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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....
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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?
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 Ļ* orbital. If so, the X-H bonding distance increases, bond weakens, stretching ...
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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?
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1answer
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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)
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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 ...
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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 ...
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1answer
574 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 Ā°C, while propanamide has a lower boiling point of 213 Ā°C. Both amides are capable of ...
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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 ...
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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 ...
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Does increasing # of hydrogen bonds decrease the strength of these bonds?
I saw the question, "Is the strength of hydrogen bonding greater in hydrogen peroxide or water?" and it reminded me of a question I had about hydrogen bonding:
If an oxygen on a water has a hydrogen ...
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Hydrogen Bonding in Water (MO theory)
Valence Bond Theory tells us that each of the āsp3ā (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-...
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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 ...
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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 ...
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1answer
491 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 ...
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2answers
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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 ...
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177 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 ...
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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-...
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1answer
359 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 ...
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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-...
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2answers
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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 ...
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668 views
Why is the intermolecular hydrogen bond between phenol and aniline stronger than the respective hydrogen bonds? [duplicate]
From NCERT class 12 part 1
The way I see hydrogen bonding is that it occurs due to intermolecular charge interaction. The more electronegative nitrogen/oxygen due to the inductive effect the ...
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1answer
792 views
Why is the melting point of hydrogen fluoride lower than that of ammonia?
The melting point of hydrogen fluoride is -83.6Ā°C, as compared to that of ammonia, which is -77.73Ā°C. How does this make any sense?
Both hydrogen fluoride and ammonia show hydrogen bonding, which "...
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1answer
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Non-conventional polymers
IUPAC defines a monomer as,
A molecule which can undergo polymerisation thereby contributing constitutional units to the essential structure of a macromolecule.
Bearing this in mind, I thought ...
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Explain the effect of intramolecular hydrogen bonding on solubilities in cold and hot water?
There is a statement given in my textbook (Cengage, Organic Chemistry (Part 1), page 4.33) which is as follows: (I edited the statement to make it simpler)
One can account for the solubilities of ...
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2answers
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What is Hydrogen bond Auto-correlation function
Can somebody explain the Hydrogen bond Auto-correlation function in Computational Chemistry (Molecular Dynamics and Simulations) and what does Intermittent and Continuous Hydrogen bond means?
Why ...
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Hydrogen bonding in chloral hydrate
Normally, chlorine doesn't form hydrogen bonds because despite its electronegativity, the size of the atom is such that its electron density is too low to form hydrogen bonds.
However, chlorine forms ...
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1answer
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Why are highly branched alcohols solid?
Usually branching (or decrease in surface area) leads to increased volatility. But in case of alcohols, my book states that:
The higher alcohols (butanols to decanols) are somewhat viscous, and ...
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3answers
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Which has stronger hydrogen bonds: water or ice?
As ice is the solid form of water and it has more hydrogen bonds than water, because it's oxygen atoms are precisely tetrahedrally positioned and each oxygen is hydrogen bonded by four neighbouring ...
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1answer
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Why only F, O and N form Hydrogen Bonds? [duplicate]
Why only fluorine, oxygen and nitrogen can form hydrogen-bonds with the hydrogen of another molecule?
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553 views
Hydrogen bond strength of trichloromethane and chloromethane
Chloromethane has a larger dipole moment than trichloromethane. Does that mean that the hydrogen bond (C-H...O type) between chloromethane and acetone is stronger than that of trichloromethane and ...
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1answer
236 views
electronegativity and hydrogen bonding [duplicate]
I have a basic idea why, but can someone just confirm, why chlorine isn't able to hydrogen bond despite the fact that it has the same electronegativity value as nitrogen.
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How to characterise lipophilicity?
I was provided with a drug compound which is filling a hydrophobic pocket. The R group is changed and effects on the potency was measured; $\ce{R = -H, -CH3, -CH2F}$ were tested. As expected, the more ...
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How to determine the pH range at which maximum hydrate is present?
Question:
Find the $\mathrm{pH}$ range at which maximum hydrate is present in a solution of oxaloacetic acid (given $\mathrm{pK_a}$ of $\ce{-COOH}$ in the left is $=2.2$ and on the right is $=3.98$):
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Strongest hydrogen bond between neutral molecules?
It is known that very strong hydrogen bonds can occur in charged systems, such as $\ce{[F-}\ce{-H+-F-]}$, while hydrogen bonds in neutral systems are much weaker in comparison.
What is the strongest ...
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How to identify hydrogen bonds and other non-covalent interactions from structure considerations?
Chemistry is governed by a wide range of interactions, from ionic and covalent bonding, or other types of strong interactions, towards weaker types of bonding, attraction, or repulsion, that typically ...
asked Feb 6 '18 at 11:27
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1answer
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Will the carboxylate groups of the citrate anion undergo hydrogen bonding?
The citrate anion of trisodium citrate has three carboxylate groups. I am concerned with whether or not there will be hydrogen bonding in water, with hydroxyl groups of other ions or alcohols.
It has ...
