Questions tagged [hydrogen]
Questions regarding the chemical properties of hydrogen and its behavior in reactions and compounds.
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Relative reacting tendency of H2/Pd towards double bond and triple bond in straight carbon chain
If both double bond and triple bond is present in a straight carbon
chain the which one (double bond or triple bond) will be reduced by
$1$ equivalent of $\ce{H2(Pd)}$ ?
My guess is that the ...
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What types of ultraviolet light will ignite hydrogen?
I saw a reaction between hydrogen and chlorine ignite in the presence of UV light. I was wondering if the same thing would happen with something like near-ultraviolet light (around 400 nm). What kinds ...
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What is the link between hydrogen production and potassium oxide?
Is there an industrial process that produces hydrogen with potassium oxide as a catalyst?
Or is there a process for the production of potassium oxide that has hydrogen as a by-product?
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Chemical reactions in plasma state
I am wondering about chemical reactions when the reactants are in a plasma state. Consider hydrogen and oxygen. Heated, these would react to form water.
If hydrogen and oxygen plasma were combined, ...
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Why does hydrogen burn with a pop sound?
Our teacher made us to do an experiment with zinc granules and hydrochloric acid.
$$\ce{2HCl + Zn -> ZnCl2 + H2}$$
We collected the hydrogen gas that was evolved in a test tube and on ignition, ...
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Can the hydride ion act as a ligand?
Hydride ion, as I know is a pretty powerful base, much stronger than hydroxide ion and cannot exist in an aqueous phase.
Can it act as a ligand in coordination compounds? Hydride ion has its ...
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Forming hydrogen sulfide from electrolysis of sodium thiosulfate
So I was doing electrolysis on two silver electrodes and sodium thiosulfate.
Some observations
The voltage drops extremely fast from 2 V to less than 1 V in 15 minutes, possibly because of the ...
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Is there such a thing as an acid without a hydrogen?
I'm in AP Chemistry and we are learning about the Brønsted-Lowry model and my teacher mentioned that "for the most part" acids have hydrogen, could there be such a thing as an acid that has no ...
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How can I generate 250 GPa to create metallic hydrogen?
In the preparation of metallic hydrogen, how does one conjure up such immense pressures?
I mean, I read that something like diamond anvils were used to contain the hydrogen, but now, in accordance ...
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Properties of metallic hydrogen
Given the possibility that metallic hydrogen may have recently been produced, and the massive media bloviation that followed, I am curious about some of the "properties" that I heard from multiple ...
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Why is the H-H Bond Dissociation Enthalpy so high? [closed]
"The H-H Bond Dissociation Enthalpy is the highest for a single bond between 2 atoms of any element."
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Why are some elements more abundant than others in the universe?
Hydrogen is the most abundant element in the universe. But what makes it so? At the time of big bang, what made certain elements more abundant than the others?
I don't find this order of abundance ...
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Why is the entropy of deuterium greater than that of hydrogen gas
Why is the entropy of deuterium more than that of hydrogen gas?
I thought about it but couldn't figure out a reason for why that would happen. Why would the number of neutrons in the nucleus ...
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Will ammonia react with gasoline mixed with ethanol?
Recently, a few South Koreans invented a car that runs on an 70% ammonia 30% gasoline fuel mix.
Trevor Brown, The AmVeh – an ammonia fueled car from South Korea, June 20, 2013.
In America, we ...
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Notation of hydrogen
$$\ce{e- + H2O -> [H$\cdot$] + HO-}$$
I was a little confused on the notation of the hydrogen in brackets ([H]) in the product side of the reaction. Why is there a dot next to it and what does it ...
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Densest hydrogen storage medium [closed]
What compounds or nanostructures contain the most hydrogen atoms per unit of volume in realistic conditions (under 1 GPa). Particularly boron-free compounds because it's to be used in sci-fi nuclear ...
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How can difference in neutron number cause a difference in ionisation enthalpies?
It’s a well known fact that protium,deuterium and tritium have the same number of electrons and protons but different number of neutrons. It is expected that their ionisation enthalpies should be same ...
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What is the nature of interstitial hydrides?
In my Chemistry book(NCERT Chemistry,Part 2, textbook for class 11, Pg 281). I found the mention of interstitial hydrides:
Unlike saline hydrides these compounds are nonstoichiometric, for
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Why do spin isomers of hydrogen (ortho and para hydrogen) change their nuclear spin with temperature variance?
My book says that ordinary dihydrogen contains 75% ortho and 25% para forms of hydrogen, while at significantly lower temperatures (like 20K) ortho and para hydrogens are 0.18% and 99.82% respectively....
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What is the difference between "atomic hydrogen" and "nascent hydrogen"?
My book (Comprehensive Chemistry by Dr. N . K. Verma, S. K. Khanna, Dr. B. Kapila) mentions two forms of hydrogen — "atomic" & "nascent".
It says that these two forms of hydrogen are more ...
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Emission Spectrum of Hydrogen and Helium?
Why do hydrogen and helium have different emission spectra? I thought that emission spectra were the result of electrons 'jumping' from one energy level to the next - since hydrogen and helium both ...
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Are nuclear spin isomers "allotropes"?
In my book there's a question:
Does $\ce{H2}$ show allotropy ? Describe its allotropes and their applications.
Wikipedia doesn't list any allotropes of $\ce{H2}$. However, when searching on the ...
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Hydrogen atom transfer between enantiomers of rac-1-phenylethanol
(Taken from Dalton Trans., 2012, 41, 13423–13428. DOI:10.1039/c2dt31781h)
I have difficulties understanding the hydrogen transfer in the image above. I always thought that hydrogen transfers followed ...
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When a molecule loses hydrogen atoms, does it become oxidised?
I had the following question on a bio test covering cell respiration and glycolysis, but I'm not sure if I agree with the answer.
When a molecule loses hydrogen atoms (as opposed to hydrogen ions),...
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Is there any substance that is liquid at room temperature and pressure that doesn't contain H as one it's constituents apart from mercury? [closed]
I want to know if there's any substance that is liquid at room temperature and atmospheric pressure that doesn't contain HYDROGEN atom(s) in its make up. Any substance dissolved in water or any ...
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Oxidation state of hydrogen in the LaNi5H intermetallic
This question is from an introductory chemistry course:
What is the oxidation state of $\ce{H}$ in $\ce{NaH}$, $\ce{HCl}$, and $\ce{LaNi5H}$?
I've looked in the textbook to no avail.
Google ...
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Difficulty understanding redox in terms of hydrogen and oxygen transfer?
I have come across 4 ways of defining oxidation:
loss of electrons
increase in oxidation number
gain of oxygen
loss of hydrogen
From these definitions, I have an idea of what I think 'oxidation' and ...
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How to calculate the magnitude of magnetic field of an orbital?
I read that according to QM the electron in the ground state orbital produces no magnetic field, if that is true, can you explain why so and in what states there is a magnetic field and how that is ...
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Hydrogenation side product: potential mechanisms for C-C bond making
In the analysis of the product mixture of a new catalytic hydrogenation reaction I'm trying out I am getting this side product molecule (in low quantities; less than 1% w/w).
Is this a likely / ...
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why hydrogen is so light?
I was studying about properties and behaviour of hydrogen and found that hydrogen is lightest element.It is so light that 1 litre of hydrogen at N.T.P weighs only 0.0980 grams.
The first statement ...
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Is hydrogen (on its own) considered an acid?
An acid is:
A molecule or other species which can donate a proton
So when hydrogen appears by itself on one side of a dissociation reaction e.g. $\ce{HOCl -> H+ + OCl-}$ is the hydrogen an ...
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Stability of ortho and para hydrogen [duplicate]
I have two books on inorganic chemistry, one says that ortho hydrogen is more stable while other says para is more stable. Even on Internet, there are websites some supporting the former fact and some ...
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Difference between Lindlar and Rosenmund catalysts
Is there any difference between the Lindlar and Rosenmund catalysts? I've checked around, and it seems the same compounds are used to make both. Is there a difference in their reactivities or are they ...
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Hydrogen gas' reducing property
I just went though a reaction wherein hydrogen gas is liberated and hence restricts the product formed to ferrous and not ferric salt. I just want to know how H2 gas gets its reducing property? It has ...
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All resonance structures of the hydrogen molecule
This answer written by Jan says that "a professor of mine claimed to have drawn some 18 (or was it 80?) different resonance Lewis structures."
Please reproduce those resonance structures of the ...
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Reduction of copper oxide by hydrogen
In the concluding part of my previous question, wouldn't there be an explosion near the hole in the tube from where the excess hydrogen is coming out instead of a steadily burning flame?
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Reduction of copper oxide by hydrogen in the lab
Why does the hydrogen which is passing continuously through the tube have to be burnt when it is passing out from the tube? Why can it not be allowed to just escape simply?
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Why is there an upper limit to the photon energy that can be observed in the discrete emission spectrum of the hydrogen atom?
I think it must have to do with the fact that an incident photon with a sufficiently high energy will ionize the hydrogen atom (i.e. the electron will be ejected). Therefore it won't show in the ...
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can protons or H+ appear as stable gas? [closed]
Can H+ appear as stable gas or they react to form H2? Can H+ appear as stable gas or they react to form H2? Can H+ appear as stable gas or they react to form H2? Can H+ appear as stable gas or they ...
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What is the position of hydrogen in the periodic table? [duplicate]
Hydrogen is not in the first group as it was before and it is now placed above the periodic table? So why is it still categorized as a metal in some books?
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Is there a reaction to get hydrogen from hydrocarbons?
Combustion of hydrocarbons reveals hydrogen, but not sure at what efficiency. Is there a reaction to get hydrogen from hydrocarbons?
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I have 6% weight by vol of hydrogen peroxide. How much water should i add to make it 3% [closed]
i read that to bleach hair we should use 3 percent hydrogen peroxide. the bottle i got is 100ml and says 6% w/v h2o2.so how much percentage of peroxide does it contain. how should i dilute it
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Alkalide compounds
I have read much more about metallic hydrides but I am totally confused about "inverse alkali hydrides" or "hydrogen alkalides" while reading refer to this. What are these compounds and how do they ...
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Can hydrogen gas reduce copper(II) ion?
I have a solution of copper(II) sulfate, and I would love to precipitate the copper metal. From looking at the standard reduction potential table, it appears that I can do this by bubbling hydrogen ...
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What is generally meant by distinct line spectrum?
In a single hydrogen atom the electron is excited to 6th orbit. The book says maximum 5 distinct spectral lines are possible when the electron comes to the ground state.
Looks like they have only ...
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Control the pressure of Hydrogen in a small container without the use of a pressure regulator
I had recently asked this question, and due to the comments and general consensus of safety concerns, I decided to re-ask the question, attacking the problem from another angle.
The Problem
I need to ...
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Limit the production of hydrogen in a small container
I have to produce hydrogen at a near-constant pressure inside of a really small container without using an automatic pressure release value. I would like the pressure to be relatively high, but the ...
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Safely storing hydrogen
I have built a solar panel which is used to add electrodes to $\ce{H2O}$ and $\ce{NaCl}$, evolving $\ce{H2}$ and $\ce{O2}$.
How can I safely store the hydrogen in the long-term?
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Electrocatalysis of Hydrogen Evolution Reaction with metal oxides
I'm new to the topic of electrocatalysis so I have a few questions. Also, I don't have much knowledge about thermodynamics, but I will try to ask anyway.
I'm looking for a material to catalyze the ...
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Standard Enthalpy of Formation of H2(g) vs H(g)
My question is somewhat related to this question. When I look at a table of standard values there are two entries for Hydrogen:
$\ce {H2(g)} $ - 0 kJ/mol
$\ce {H(g)} $ - 218 kJ/mol
I understand ...
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