liljoe086
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water chem
HI, new here but I thought it best to just dive right in.
We all know the combusion of H and O we get water
My question is, is this reaction possible
2H- + O + (activation energy) => H2O + heat
can you use hydrogen ions to make water.
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Nerro
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Chemistry doesn't get much more basic than this...
First off, you have the reaction wrong it goes as follows:
2H<sub>2</sub> + O<sub>2</sub> -> 2H<sub>2</sub>O
And second, hydride ions will not exist freely and as such they won't react with oxygen to form water. More over, where would the charge go? You have
2- on the left and no charge on the right! You can't just turn electrons into heat like that it doesn't work that way.
#261501 +(11351)- [X]
the \"bishop\" came to our church today
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liljoe086
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| Quote: | Originally posted by Nerro
Chemistry doesn't get much more basic than this...
First off, you have the reaction wrong it goes as follows:
2H<sub>2</sub> + O<sub>2</sub> -> 2H<sub>2</sub>O
And second, hydride ions will not exist freely and as such they won't react with oxygen to form water. More over, where would the charge go? You have
2- on the left and no charge on the right! You can't just turn electrons into heat like that it doesn't work that way. |
Opps sorry about the equation, im not sure how to make a subscript  so i left it
in a single form but yes you need the diatomics.
OK then take me back to the basics. What actually occurs in the basic equation. The 2 atoms want to go to a lower energy state, but requires a push
for the reaction to happen (activation energy). When the right amount is added, the reaction can happen. Normal H has 1 e- and O has 8. Tell me what
occurs.
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12AX7
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The molecules have to be broken. A small amount of molecules posess a large amount of energy (read up on thermal statistics for why), and the number
increases with temperature. Above a few electron-volts, molecules dissociate and produce radicals: O2 <--> 2O. Oxygen atoms are very reactive.
One might steal electrons from a nearby hydrogen molecule as O + H2 = H2O, thereby leaving another oxygen free to do the same. Photodissociation can
cause the same thing without heat. In this case, you'd want light in the 200nm range (UV-C), which carries enough energy to break oxygen atoms.
The resulting water molecule carries a lot of energy and may dissociate: H2O <--> H + OH. Hydroxyl radicals are nasty oxidizers; this reaction
allows contaminants to be cleared from the atmosphere (hydroxyls react with methane, carbon monoxide, hydrocarbons, etc. to give H2O and CO2, etc.),
albeit slowly. The molecule's energy may also smack into other molecules, breaking off another oxygen atom, say. There are many possible reactions,
but this is the jist of it.
If few of these radicals are present, the reaction proceeds very slowly. If a critical number of them exist at any point, the reaction snowballs and
the mixture is able to explode by a cascade of these reactions.
Note that I have done nothing with electrons. Nature tends to make charge-neutral species. H2O <--> H+ + OH- proceeds to some extent (namely,
10^-14) in liquid water, but radicals are preferred at high temperature. It's more useful to think in terms of atoms and their reactivity (which is
due to unpaired electrons) than the number of electrons. The number of electrons goes more into predicting molecular nature (Lewis dot structures and
VSEPR theory for example).
Tim
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YT2095
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sounds almost like a Fuel Cell.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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liljoe086
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| Quote: | Originally posted by 12AX7
The molecules have to be broken. A small amount of molecules posess a large amount of energy (read up on thermal statistics for why), and the number
increases with temperature. Above a few electron-volts, molecules dissociate and produce radicals: O2 <--> 2O. Oxygen atoms are very reactive.
One might steal electrons from a nearby hydrogen molecule as O + H2 = H2O, thereby leaving another oxygen free to do the same. Photodissociation can
cause the same thing without heat. In this case, you'd want light in the 200nm range (UV-C), which carries enough energy to break oxygen atoms.
The resulting water molecule carries a lot of energy and may dissociate: H2O <--> H + OH. Hydroxyl radicals are nasty oxidizers; this reaction
allows contaminants to be cleared from the atmosphere (hydroxyls react with methane, carbon monoxide, hydrocarbons, etc. to give H2O and CO2, etc.),
albeit slowly. The molecule's energy may also smack into other molecules, breaking off another oxygen atom, say. There are many possible reactions,
but this is the jist of it.
If few of these radicals are present, the reaction proceeds very slowly. If a critical number of them exist at any point, the reaction snowballs and
the mixture is able to explode by a cascade of these reactions.
Note that I have done nothing with electrons. Nature tends to make charge-neutral species. H2O <--> H+ + OH- proceeds to some extent (namely,
10^-14) in liquid water, but radicals are preferred at high temperature. It's more useful to think in terms of atoms and their reactivity (which is
due to unpaired electrons) than the number of electrons. The number of electrons goes more into predicting molecular nature (Lewis dot structures and
VSEPR theory for example).
Tim |
Ok how does that help me  . As an aside I also believe the same range of UV-C is
need to photodissociate H
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Nerro
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Oxygen on its own has 8 electrons, 2 s electrons in the first "shell", two s electrons in the second shell and 4 p electrons in the second shell.
Chemists denote this electron-configuration as 1s<sup>2</sup>2s<sup>2</sup>2p<sup>4</sup>. Now oxygen is
in it's lowest energy state when it has the same configuration as the first noble gas that comes after it on the periodic table. This is Neon which
has two protons and two electrons more than oxygen which means it has the following electron configuration
1s<sup>2</sup>2s<sup>2</sup>2p<sup>6</sup> (which is commonly denoted as [Ne]).
Hydrogen has 1 electron which means its electron configuration is simply 1s<sup>1</sup>, the next noble gas on the list is He which has
two electrons so its electron configuration is 1s<sup>2</sup>.
This means that oxygen lacks two electrons and that hydrogen lacks one electron.
So when two hydrogen particles share their electrons with an oxygen particle they can all say they have enough electrons, the hydrogen particles will
form a two-electron bond with the oxygen particle which means they will have two electrons in their outer shell which makes them a little like He and
the oxygen particle has 2 extra electrons from the hydrogen which makes it a little like Ne. Now there are still as many electrons as there are
protons but all particles have electron configurations that resemble that of the closest noble gas.
I'm not really going into it too much right now, does this make sense to you? If it does not just draw the lewis structure for water and you will see
that the hydrogen's each have two electrons in their outer shell and that the oxygen has 8 electrons in it's outer shell.
#261501 +(11351)- [X]
the \"bishop\" came to our church today
he was a fucken impostor
never once moved diagonally
courtesy of bash
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liljoe086
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| Quote: | Originally posted by Nerro
Oxygen on its own has 8 electrons, 2 s electrons in the first "shell", two s electrons in the second shell and 4 p electrons in the second shell.
Chemists denote this electron-configuration as 1s<sup>2</sup>2s<sup>2</sup>2p<sup>4</sup>. Now oxygen is
in it's lowest energy state when it has the same configuration as the first noble gas that comes after it on the periodic table. This is Neon which
has two protons and two electrons more than oxygen which means it has the following electron configuration
1s<sup>2</sup>2s<sup>2</sup>2p<sup>6</sup> (which is commonly denoted as [Ne]).
Hydrogen has 1 electron which means its electron configuration is simply 1s<sup>1</sup>, the next noble gas on the list is He which has
two electrons so its electron configuration is 1s<sup>2</sup>.
This means that oxygen lacks two electrons and that hydrogen lacks one electron.
So when two hydrogen particles share their electrons with an oxygen particle they can all say they have enough electrons, the hydrogen particles will
form a two-electron bond with the oxygen particle which means they will have two electrons in their outer shell which makes them a little like He and
the oxygen particle has 2 extra electrons from the hydrogen which makes it a little like Ne. Now there are still as many electrons as there are
protons but all particles have electron configurations that resemble that of the closest noble gas.
I'm not really going into it too much right now, does this make sense to you? If it does not just draw the lewis structure for water and you will see
that the hydrogen's each have two electrons in their outer shell and that the oxygen has 8 electrons in it's outer shell. |
Actually that is what is was looking for ty
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12AX7
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| Quote: | Originally posted by liljoe086
Ok how does that help me . As an aside I also believe the same range of UV-C is
need to photodissociate H |
Well, you didn't say what it is you want to know about. It sounded like combustion (which is a free radical process). It turns out you wanted to
know about covalent bonding...
Tim
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