Questions tagged [hydrogen]

Questions regarding the chemical properties of hydrogen and its behavior in reactions and compounds.

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5
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1answer
552 views

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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1answer
1k views

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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1answer
960 views

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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1answer
480 views

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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1answer
438 views

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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1answer
2k views

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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1answer
3k views

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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1answer
340 views

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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3answers
2k views

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 ...
0
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1answer
260 views

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 ...
3
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1answer
119 views

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 ...
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0answers
41 views

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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1answer
65 views

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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1answer
425 views

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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1answer
20k views

Standard Enthalpy of Formation of H2(g) vs H(g)

My question is somewhat related to this quesion. 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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1answer
118 views

Production of hydrogen through the reaction of aluminium metal and sodium hydroxide

If I have a solution of 25% $\ce{NaOH}$, and I simply add a cut-up aluminium can or some aluminium foil, will it react into hydrogen and sodium aluminate? In principle this reaction should happen, ...
0
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1answer
536 views

H2 Triplet State

How does $\ce{H2}$ triplet state exist if there are electrons in both bonding and antibonding ($1\sigma$ and $1\sigma^*$) orbitals? Or am I being taught the hypothetical triplet states of the ...
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2answers
454 views

Is it possible to efficiently convert hydrogen to methane?

According to this wikipedia page, hydrogen can combine with the carbon found in carbon steel to form some methane inside the steel, weakening it. Is is possible to convert hydrogen to methane by ...
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0answers
51 views

Combustibility of gas/carbon dioxide mix

Via electrolysis I produced an ethane/hydrogen/carbon dioxide mix. Normally, there is 1 part ethane, 1 part hydrogen and 2 parts carbon dioxide. If I simply used a Bunsen burner with air hole closed ...
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1answer
455 views

Hydrogen bonding in complex compounds?

Does the water molecules in coordinated water (where water acts as ligand) form hydrogen bonding with other complex molecules? Will the water molecules inside the complex form intramolecular hydrogen ...
15
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1answer
235 views

Photoionisation microscopy of hydrogen - where are the p orbitals?

In this Physics Review Letters article, which was published in 2013, but I found recently, the authors report photoionisation microscopy images of hydrogen atoms in various electronic states. A. S....
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5answers
1k views

How much energy is stored when H+ is converted to H2?

I'm doing a write-up for this for my students: Source: Amirav Research Group (Facebook) The energy of formation of isopropyl alcohol is $-318.2~\mathrm{kJ/mol}$ (kilojoules per mole), that of ...
3
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1answer
727 views

Deuterium removal from water

What percentage of deuterium might be removed from water after a typical electrolysis procedure? From a post on this site I read that, "In the first stage, $\ce{NaOH}$ solution (initially $0.5\rm{M}$) ...
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2answers
1k views

What exactly happens when vegetable oil is partially hydrogenated?

My current assumption is that partial hydrogenation requires a polyunsaturated fat, because partial implies at least one but not all, which means there must be at least two double bonds in the fat, ...
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2answers
548 views

Is lithium hydride a salt?

Hydrogen is generally considered a non-metal, and a non-metal and a metal often makes a salt. However, lithium hydride seems like a special case. The wikipedia article does not clearly state if the ...
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0answers
48 views

Hydrodehalogenation of aryl chlorides

Palladium is the "go to" heterogeneous catalyst for dehalogenating aryl chlorides using hydrogen. What are the chemical (not economic) reasons for other precious metal catalysts not being as common or ...
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1answer
1k views

What is the relation between dielectric constant and hydrating tendency?

What is the relation between dielectric constant and hydrating tendency? Could someone also explain both terms?
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2answers
247 views

How difficult is it to produce diatomic hydrogen?

Just to preface this, I have a very basic understanding of chemistry, so forgive me if what I'm asking is super basic. How difficult is it to produce diatomic hydrogen? I've been doing some reading ...
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2answers
4k views

Why are hydrogenation reactions exothermic?

I learned that all reactions that yield hydrogen are endothermic (such has reforming) and reactions that use up hydrogen are exothermic (FCC cracking, hydrogenation, etc.). But why is this so? I know ...
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1answer
79 views

Water splitting ways [closed]

Do you know the frequency you can split hydrogen from the water bonds? I have doing at now but i need to absorb more than 3 liters gas hydrogen per minute. My device working only with one ampere by ...
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2answers
17k views

How many bonds can Hydrogen make?

Recently I saw a video which told me that Hydrogen has a valency of 1, i.e, Hydrogen can only bond with 1 other atom. But since hydrogen wants a complete shell, it can have 2 covalent bonds with 2 ...
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2answers
7k views

Why doesn't hydrogen displace metals from their oxides?

As I understand it, a displacement reaction is where a more reactive element kicks out a less reactive element from a compound. For example, chlorine is more reactive than iodine, so chlorine will ...
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2answers
390 views

Can gaseous hydrogen and gaseous oxygen be compressed without reaction?

I'm looking into building a clean Bunsen-style burner (or rocket engine - I haven't decided yet). I will be using electrolysis to extract hydrogen and oxygen from water, but the apparatus I am ...
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2answers
2k views

Why this doesn't hydrogen peroxide decompose into hydrogen and oxygen?

I'm trying to understand why hydrogen peroxide doesn't decompose into $\ce{H2}$ and $\ce{O2}$, but instead into $\ce{H2O}$ and $\ce{O2}$.
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1answer
2k views

Does the hydrogen ion actually exist? [duplicate]

A chemistry test I did was an IGCSE test. One of the questions was Is Hydrogen Chloride ionic or covalent? Now, on a sheet I have been given, it states the hydrogen ion is $\ce{H+}$. So, it forms ...
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1answer
393 views

Hydrogen's confusing purple glow

While reading about hydrogen on Wikipedia, I read that hydrogen has a purple glow in its plasma state. This confused me because although hydrogen is present in its plasma state on the sun, the sun ...
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1answer
2k views

Specific Heat Capacity of Heavy Water

Water has an unusually high specific heat capacity due to it's hydrogen bonds. Why is it that the change in isotope causes a 10% difference in the heat capacity? How does the added neutron in the ...
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3answers
23k views

Why can't Pd/C and H2 reduce both the alkene and carbonyl portions of α,β-unsaturated carbonyls?

Why is it that the major product of the reduction of chalcones the ketone and not the monoalcohol? In other words, Why isn't the major product a benzyl alcohol? From what I understand, catalytic ...
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2answers
699 views

What happen to the Salt in Water Electrolysis [closed]

I haven't found yet what happen to the Salt Ions in Water during Electrolysis and is there an Electron Flow or Ion Flow. I have expierienced strong magnetic Forces between the Electrodes but couldnt ...
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2answers
7k views

Why is there a need of polar coordinates to solve the Schrödinger wave equation for the hydrogen atom?

Why is there a need of polar coordinate to solve the Schrödinger wave equation for the hydrogen atom? I went through some standard text books but I am feeling rather confused about the explanation.
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3answers
3k views

Hydrogen displaces lead?

there was a reaction in my book. It is as follows: $\ce{PbO + H2-> Pb + H2O}$ My question is Hydrogen is below lead in the reactivity series. Then how is this reaction possible?
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2answers
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Why is there no neutron in protium?

My chemistry teacher once told me, that every atom should have at least as many neutrons as protons, to keep the electrons from crashing into the nucleus. Protium, however, doesn't even have ...
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0answers
62 views

Hydrogen phase transition

A sample of hydrogen at a pressure of 7.10×10-2 atm and a temperature of 26.4 K is compressed at constant temperature to a pressure of 18.5 Which of the following are true? 1. One or more phase ...
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1answer
3k views

Stability of ortho- and para-hydrogen

can the stability of ortho-hydrogen greater than para-hydrogen can be stated as this? The intrinsic energy of ortho is greater than para-hydrogen and also with rise in temperature %of ortho form ...
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1answer
79 views

Is there a non-violent, practical way of making hydrochloride with only Hydrogen and Chlorine?

A way of making HCl gas is to put Chlorine and Hydrogen into a test tube and expose it to UV light. This reaction is however fast and strong and I would like to store the Hydrochloride from it. ...
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0answers
59 views

Converting hydrogen to methane

I am in need of small amount of pure methane for laboratory purpose. I have hydrogen generator in the lab. Is there a possibility of generating methane from hydrogen ? May be make hydrogen flow ...
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1answer
7k views

Calculate how much hydrogen or oxygen will be produced in the electrolysis of water

Is there a way to exactly calculate the quantity of hydrogen or oxygen in a water electrolysis? I am thinking of a plain and simple electrolysis like an anode and kathode in salted water separating ...
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1answer
5k views

what is difference between H+ and proton

What is difference between $\ce{H+}$ and a proton?
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1answer
59 views

Hydrogen visible transitions

When dealing with electrons and the electromagnetic spectrum, why are there only four visible transitions in the hydrogen atom?
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Why are isotopes of hydrogen the only ones with special names?

Why does no other element but hydrogen get special names for its isotopes?