The Stack Overflow podcast is back! Listen to an interview with our new CEO.

Questions tagged [hydrogen]

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

Filter by
Sorted by
Tagged with
5
votes
2answers
11k views

Why is platinum used as a catalyst in fuel cell electrodes (and elsewhere)?

I have rather basic knowledge of chemistry (at the level of a first year college class). But maybe somebody can still clarify with some simple words: What makes platinum a good catalyst for the ...
1
vote
1answer
21k views

How do I calculate the change in energy of an electron transition?

What are the $\Delta E$'s of the transitions of an electron from $n=5$ to $n=1$ and from $n=5$ to $n=2$ in a Bohr hydrogen atom? The wavelength of the first electron transition is $\lambda_1=409~\...
5
votes
2answers
1k views

Will compressed hydrogen float in air?

Imagine a container of fixed volume is taken and hydrogen gas is filled in it, as a result the container floats in air. But if in the same container is filled with so much hydrogen that the hydrogen ...
4
votes
2answers
618 views

The ionization energy of H₂⁺ molecule ion

I am trying to compute the ionization energy of $\ce{H2+}$ molecule ion from the electronic energy spectrum. The question is whether one should use the purely electronic Hamiltonian or the Hamiltonian ...
10
votes
1answer
4k views

Can 1 mole of H2 react partially with one mole of O2?

I am currently studying stoichiometry (high school level) and we came across the following equation in school: $\ce{2H2 + 1O2 -> 2H2O}$ which is clear to me. We learned in school that reactions ...
8
votes
2answers
2k views

Is real water made up of heavy water and light water?

I need to know, is real water made up of heavy water which is formed with deuterium, and light water which is water by protium? We know that hydrogen has three major isotopes, including protium and ...
2
votes
3answers
5k views

Is it dangerous to inhale the steam coming from electrolysis of salt-water solution

Is chlorine in there that accumulates (at the anode) and emerge out as chlorine gas? I was worried since I added a pinch of salt to the steamer in order to hasten the heating of tap water when I ...
1
vote
1answer
146 views

Why do batteries specifically vent *hydrogen* in the event of abuse?

When a battery is subject to overcharging or overdischarging (including attempts to recharge a primary cell), it may vent hydrogen. It seems that every type of electrochemical battery I've read about ...
5
votes
2answers
33k views

Different reactions of clean and rusty iron nails in vinegar (acetic acid)

I have submerged a iron nail in vinegar twice recently. What is puzzling me is the different results each time. The first time I submerged it, it was covered in rust. When I put it in the solution of ...
17
votes
4answers
94k views

Why are there multiple lines in the hydrogen line spectrum?

Hydrogen has only one electron, yet it exhibits multiple lines in a spectral series, why is this?
2
votes
3answers
9k views

Can a spark ignite hydrogen?

Can a spark ignite hydrogen? Also, what about the tip of a cigarette? I've heard that hydrogen is very explosive. Thanks
4
votes
3answers
4k views

Can natural gas appliances run on Hydrogen?

Can natural gas appliances run on Hydrogen? If so, does the appliance have to be modified and how significant of a modification would it need? Thanks
5
votes
2answers
3k views

Finding Pv in Pv=nRT for molecular hydrogen

I'm attempting to write a small program that will calculate the values for the Ideal Gas Law, specifically for molecular Hydrogen (H2) in space. Eventually, this will grow to be a sort of "simulator",...
13
votes
1answer
11k views

If electrolysis splits water, why does only either hydrogen or oxygen (but not both) bubble up on one pole?

If electrolysis splits water, then that means that $\ce{H2O}$ is split into $\ce{H}$ and $\ce{OH}$ or $\ce{O}$. How come that if a water molecule is split at e.g. the negative pole (anode), only the ...
0
votes
2answers
6k views

How to find the molecular weight of a given gas based on its density?

The density of a gas $\ce{X}$ is $10$ times that of hydrogen. In that case, what is the molecular weight of gas $\ce{X}$? Well what I've done up to now is this: The molecular mass of hydrogen is $M(\...
5
votes
1answer
2k views

Delta G for Standard Hydrogen Electrode reaction

I’m dealing with electrochemistry problems. For the following reaction $$\ce{2H+ +2e- <=>H2}\quad E^\circ=0\ \mathrm{V}$$ Does it make sense to say $$\Delta G^\circ=-nFE^\circ=0$$ Which would ...
2
votes
2answers
760 views

Palladium hydride forming water and heat at room temperature

I just read that saturated palladium hydride, $\ce{PdH}$0.7, when exposed to oxygen will generate heat and water on it's surface, $\ce{4 H}$(Pd) $\ce{+O2}$(g) $\ce{\to 2 H2O}$(g, l). What is going on?...
3
votes
1answer
246 views

Hund's rule & different H₂ molecules

Does Hund's rule allow both of the following scenarios? Filling each orbital with a single electron, so that a sub-shell, at first, only electrons with a negative spin Filling each orbital with a ...
29
votes
1answer
538 views

How does Palladium dissociate H₂ so easily?

If I understand correctly, $\ce{H2}$ in the presence of $\ce{Pd}$ readily dissociates as it dissolves into the metal. With the dissociation energy for the $\ce{H—H}$ bond being so large, how is this ...
6
votes
2answers
67k views

Why does the hydroxide ion have a negative charge?

I've been studying the roles of hydroxide & hydronium in acids and bases, and it was mentioned that a hydroxide ion (OH-) has a negative charge. Can someone give me a layman's explanation of what ...
8
votes
1answer
173 views

Why would the loss of H₂ to space mean that the Earth's geochemistry would be based on acid/base reactions?

I am reading a paper[1] that contains the line: Most of the $\ce{H2}$ in the Earth's mantle escaped to space early in the Earth's history; consequently, the overwhelming majority of the abiotic ...
6
votes
1answer
3k views

Samsung's S-Plasma Ion - scientific basis

Has anyone come across a scientific study of the S-Plasma Ions that Samsung claims will purify air from microbes, allergens and free radicals? I would prefer publicly available research findings. The ...
15
votes
1answer
637 views

Are there any examples of nuclear spin isomers having consequences for chemical reactivity?

Ortho- and parahydrogen are two forms of the $\ce{H2}$ molecule that are distinguished by their pairing or antipairing of nuclear spins, giving rise to metastable singlet (ortho-) and triplet (para-) ...
12
votes
2answers
1k views

Why is slush hydrogen at the triple point?

Slush hydrogen is a mixture of liquid and solid hydrogen at the triple point considered as a possible vehicle fuel. What is the need of having it at the triple point? Couldn't any other set of ...
31
votes
1answer
10k views

Why are there two Hydrogen atoms on some periodic tables?

Most periodic tables only feature one Hydrogen atom, on the top of the first group. But some, like the one I was given, also show Hydrogen in the 7th group, to left of Helium. Why are there two ...