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What the Heck? Chemistry Experts Needed NOW!

  1. Jan 20, 2012 #1
    Okay so I was just sitting around and thinking about Hydrogen (weird I know) when I realized that a hydrogen ion is just a proton. So how do we distinguish between molecules such as Cl+ (Chlorine with extra hydrogen) and HCl?
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  3. Jan 20, 2012 #2


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    Cl+ is not Chlorine with an extra hydrogen; it is chlorine missing an electron.

    No matter how many electrons it gains or loses, an atom with 17 protons in its nucleus will be chlorine.

    Making HCl is not done by adding a proton to the nucleus, it is done by bonding a H+ with a Cl-. But they remain distinct atoms, just joined by a valence bond.

  4. Jan 20, 2012 #3
    Ah. You're right. What I should have said is how do you tell the difference between HCl and Ar+. Not Cl+.
  5. Jan 20, 2012 #4


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    Well, Argon is a noble gas. Because it has 18 protons, it wants 18 electrons and gets them from wherever it can. This makes it neutral and inert. So it doesn't react strongly at all with anything.

    HCl is completely different.
    Cl has 17 protons, and therefore to be neutral, it needs 17 electrons. But 17 electron leaves its outermost orbital with a hole that wants to be filled. When an electron fills it, that makes it -.

    Same with H. To be neutral, it needs one electron, but it's easy to strip that electron off, leaving it +.

    Now you've got two atoms, both of which - if they stick together - can ride the fence between being electrically neutral and having their orbitals full.
    Last edited: Jan 20, 2012
  6. Jan 20, 2012 #5


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    Apparently you are thinking that the proton is added to the chlorine nucleus. It is not. HCl molecule has two nuclei bonded together and separated by about 127 pm (compare that to the radius of a nucleus - which is in the fm range).
  7. Jan 21, 2012 #6
    Correct... but partially... Proton does not have a nucleus but H+ ion has! Hydrogen ion is formed by loss of 1 electron from its valence shell. Still mass of Hydrogen ion will be very very very and very slightly more than a proton.

    A Cl+ ion does not exist !( Also Cl+ is not chlorine with extra hydrogen. If it would have existed then it would be chlorine with one less electron and protons - electrons = 1) Atomic number of chlorine is 17 and mass number of it is 35.5 .

    Electronic configuration : 2,8,7
    So proton = electrons = 17 here.
    Now it need one more electron in its valence shell to complete its octet. When it gains one electron the charges present in it will be
    +17-18 = -1
    So chlorine ion will be Cl- and not Cl+ !
    Chlorine can't just loose electron ! Because it has high nuclear force. Moreover it has to become stable ! So it just can't loose 1 electron and form Cl+ ion !

    HCl ? HCl acid or HCl gas ? Here HCl gas would be formed by polar covalent bond. There will be sharing of electron pair between hydrogen and chlorine and net electronegativity towards chlorine. HCl acid is formed by ionic bond in water or aqueous solution. Hydrogen gives one electron to chlorine.

    Also Ar+ does not exist ! Argon is a noble gas. It has complete octet - 2,8,8 ! Why would it loose one electron ? By absorbing energy ? No , it will not.

    Argon was discovered with 18 protons and 18 electrons. It did not get them from anywhere. Also chlorine was discovered with 17 electrons and 17 protons. It did not get the electrons from anywhere. Every element when exist independently as a whole is neutral. Ionic elements CANNOT exist on their own until they form a bond or something.
    Last edited: Jan 21, 2012
  8. Jan 21, 2012 #7


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    Have you ever heard about Cl ionization energy? How do you think, what does it mean "to ionize Cl"? And where do we know the first ionization energy from? It was measured experimentally as 1251.1 kJ mol-1. Now think again whether Cl+ exists or not.

    I did my best to understand what you wrote - but I failed.

    Sigh. Yes it will. It will absorb 1520.5 kJ mol-1. Every ionization table has this information.

    Please stop commenting on things you have no idea about.
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