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18

Yes, sodium metal is also going to react exothermically with salt water or any other aqueous solution as long as it comes in contact with water: $$\ce{Na (s) + H2O -> Na+ (aq) + OH- (aq) + 0.5 H2 (g)}$$ eventually leading to explosion of hydrogen-oxygen mix forming near the water surface. Presence of sodium chloride in salt water isn't going to ...


7

I am not sure how to elaborate much beyond saying that yes, there are bound states of $\ce{HHe^{2+}}$. I cite three papers below which give numerical calculations of various states, ref. 1 gives calculations for the lowest 20 states of the system. It appears to be that the 1s$\sigma$ is not a bound state in this system, but the 2p$\sigma$ state is bound. I ...


6

The answer that will satisfy you depend on how familiar you are with the mathematics and principles of quantum chemistry. So, let's start small. Hydrogen atom. Exact expressions for eigenfunctions for the Hydrogen are known, they are the orbitals we know and love(?). Although the electron can be in any combination of eigenfunctions, it can only stay that ...


6

The key to the answer is understanding how FID works. The hydrogen flame has a minimal flame ionisation, what is needed for the low signal baseline. Incoming organic molecules from the HPGC column create in the flame a lot of ions and increase the flame electric conductivity. Using alternatives causing higher ionisation would decrease FID sensitivity that ...


6

You can define the size of atoms and molecules in various ways. You can, for instance, derive a measure of the size of a hydrogen molecule from the density of solid hydrogen: Solid hydrogen has a density of 0.086 g/cm3 making it one of the lowest-density solids. From the above you can derive an effective radius for $\ce{H2}$ of $\pu{2.10 Å}$, which is ...


6

The easiest way to grow diamond through chemical vapor deposition (CVD) is on a heated filament, which just takes a few watts. You'd need a low-pressure chamber (~30 torr, or ~0.04 atm) with gas-tight fittings for electricity, feed-gas of ~1% $\ce{CH4}$ and ~99% $\ce{H2}$ and $\ce{Cu}$, $\ce{Ti}$, $\ce{W}$ or $\ce{Ta}$ filaments. Since this is a flow-...


5

You have two errors in your code, one minor and one major. The minor error is in your multiplication function. The value you return should have $\pi^{3/2}$, but the way it is arranged now the power is only being applied to the denominator. The major error is how you are normalizing your overlap integrals. You can't simply divide $\langle1|2\rangle$ by $\...


5

Well, one either adds it on purpose: In order to reduce the defect volume - by passivating the dangling bonds. Unsaturated silicon atoms in a-Si is a serial killer of charge carriers. But then the issue is the SWE - you have to handle it somehow. Options are few but research is being done. The common way of handling it right now is to be honest about it. ...


4

In electrochemistry, the rate of electrolysis depends on rate of charge entering the cell. Second most important point is that one can either control potential or current but not both during electrolysis i.e. you cannot have both values set. If you are fixing potential at 2.5 V, the value of current is not in your hand. I don't think Ohm's law remains valid ...


3

Sodium catches fire even in humid atmosphere. Salt water will make no difference. It will react with water in solution of salt in water, and the heat evolved will be very high and will vapourize sodium and it will fly away and may cause injuries. Do not do this at home.


3

To meet your brief of a) performing a hydrogenation and b) using Raney nickel, but performed in the safest manner, I would use aluminium-nickel alloy. This is cheaper than sponge/Raney nickel and easier to handle i.e It's not pyrophoric until activated. I would advise the use of nitrogen, but not a sweep as it can be detrimental to the procedure I'll ...


3

Short answer: yes, if you want to store the same amount of hydrogen and on condition that you do not mess with pressure. Long answer: I'll skip some intermediate physicochemical derivations for brevity. The phenomenon we are dealing with is called adsorption. Perhaps, the simplest theoretical explanation of adsorption was given by Langmuir. Langmuir ...


3

Your question is in fact quite general in quantum mechanics and does not depend on H atoms or any atoms for that matter. If a perfect experiment is repeated under the same conditions and in exactly the same way then what will be the outcome? Surely we would expect the same answer? In general this is not true, and this is not due to experimental ...


2

The scheme starts with the production of OH radicals since Hydrogen dissociation is very endothermic (432 kJ/mole) compared to $\ce{H2 + O_2 \to 2OH\cdot}$ which is the initiation reaction with $\Delta H^{\mathrm{o}}_{298} = 72$ kJ/mole. There is a propagation reaction and two chain branching reactions and gas phase termination as well as wall termination ...


2

The bubbles are still hydrogen. Transition metal salts are generally much weaker acids than whatever you put your magnesium ribbon into for your hydrogen control. So you get less gas for the candle flame to react with when you use the transition metal salt, which I am sure you saw. That the decreased amount of gas still popped, which is basically a low-...


2

Many nuclear power plants use so-called "passive autocatalytic recombiners" for the catalytic oxidization of hydrogen that could be released into the containment in the event of severe accidents. (Note that the affected units of the Fukushima-Daiichi plant did not have such equipment.) The catalytically active materials, typically platinum and/or palladium, ...


2

You guessed it right that hydrogen and oxygen mixtures will remain stable. Someone in Harvard waited for >30 years and found very little water if any. As you said, there is a energy barrier. What type of materials can lower this barrier? Catalysts. The electrode materials require some catalysts such as platinum or nickel. Of course, making cheaper and ...


2

Another fundamental aspect of using hydrogen in gas chromatography is the so-called van Deemter curve. The curve shows the linear velocity of the gas on the x-axis and plate heights on the y-axis. It can be shown that by using hydrogen one can obtain the best efficiency as compared to any other gas. And of course, hydrogen is required for burning the ...


2

It would be nice to have a full chromatogram rather than a cropped one to see how other peaks look like. The phenomenon of odd behavior of hydrogen with helium as carrier gas with TCD detector in quite well known, but I am not sure if it has been investigated in detail in the literature or not. Hydrogen has higher thermal conductivity than helium. Ideally ...


2

The thermodynamics are always the same. If you go from carbon monoxide to methane, there is only one final enthalpy, and if you have the choice of going to methane or methanol the thermodynamically preferred product is always the same. The difference indeed less within the different pathways and the activation barriers needed to get from one intermediate to ...


1

Electrostatic repulsion between electrons is the key to understanding $\ce{H-}$. The electrons might be delocalized, but they are also correlated - they avoid each other. Both electrons of the hydrogen ion have the same energy level and they don't shield the charge of the core from one another. The Aufbau and Pauli exclusion principles (and the ...


1

A few binary metal hydride candidates: Magnesium hydride gives about 0.11 grams of hydrogen per cubic centimeter, and unlike water it can release its hydrogen leaving the element behibd on simple heating. It does, however, require 287°C to decompose, limiting reversibility. Lithium hydride offers nearly the same hydrogen density as the magnesium compound ...


1

There has been a lot of promising buzz around hydrogen. Many people believe that hydrogen can be used as an energy carrier to replace other fuels like gasoline in the near future. One of the largest challenges to use hydrogen in a wide scale is its storage after hydrogen is produced. Some storage technologies have currently been developed. Yet, according to ...


1

Hydrogen is the only element with thermal conductivity greater than helium ($0.182$ vs $\pu{0.151 W\,m^{-1}K^{-1}}$ at $\pu{25 ^{\circ}C}$) as M. Farooq pointed out (cf., thermal conductivity of $\ce{N2}$ is $\pu{0.026 W\,m^{-1}K^{-1}}$ at $\pu{25 ^{\circ}C}$). The mixtures of $\ce{H2}$ in $\ce{He}$ at moderate temperatures exhibit varying thermal ...


1

Well I'd say this is not that easy to answer. First of all, how much does the activity series really relate to the electronegativity? For elements like Fluorine it fits pretty well but according to the activity series Gold is quite noble as well and while it's electronegativity might be high among the metals but in comparison to the non-metals still quite ...


1

Yes, and Brønsted, Lowry and others generalized the concept of acid to be a proton donor and base a proton acceptor, no matter what solvent system. (There is also the Lewis definition of an acid, which has an empty orbital capable of accepting an electron pair from a Lewis base. These two definitions may overlap for certain chemicals.) As to the reason that ...


1

I built something similar to use as oxy /hydrogen welding and cutting. Basically I generated the gasses over water by electrolysis using graphite electrodes and a solar panel. The oxygen and hydrogen were collected separately in tanks made from plastic buckets, in, and separated by, a water bath. The gasses were led out via taps in the bottom of each bucket ...


1

In gaseous/plasmatic phase, there is no difference - $\mathrm{p}$ and $\ce{H+}$ are synonyms for a proton. The former ( p, proton ) is more often used by physicists in subatomic particle context, the latter by chemists in hydrogen properties/behaviour context. In polar solvents like water or liquid ammonia, "naked" protons nor electrons cannot exist, but ...


1

There are many software packages that do what you request. PHENIX, Schrodinger, SCWRL4. It depends on how accurate you want, and options for pH etc.


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