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    Ni(CO)4
    What are the oxidation numbers on each element?

    I don't know about C or Ni so I'm stuck

    Also...

    1) Peroxides have oxy. no. of -1. Why is H202 a peroxide and not NO2? Is it because peroxides must have a single c-c bond?

    2) What is a superperoxide? My teacher says they have a -1/2 oxidation no.
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    (Original post by Phalange)
    Ni(CO)4
    What are the oxidation numbers on each element?

    I don't know about C or Ni so I'm stuck

    Also...

    1) Peroxides have oxy. no. of -1. Why is H202 a peroxide and not NO2? Is it because peroxides must have a single c-c bond?

    2) What is a superperoxide? My teacher says they have a -1/2 oxidation no.
    CO is carbon monoxide, itself has zero charge. You are probably missing the supposed 2+ for the compound Ni(CO)4, which is really Ni2+.
    - If that is not the case, then, usually oxygen is taken as -2, see if you can work something out from there.

    1) a peroxide comes from the fact that it is the O-O bond. ie H-O-O-H
    this is the peroxide bond. NO2 is nitrogen dioxide, O=N=O, not a peroxide. peroxide doesn't have carbon, so no C-C bond.

    superoxide is an anion of oxygen with the chemical formula O2-.
    2 is a superscript.

    Hence, 2(oxygen charge) = -1 so each oxygen has -1/2 charge
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    (Original post by shengoc)
    CO is carbon monoxide, itself has zero charge. You are probably missing the supposed 2+ for the compound Ni(CO)4, which is really Ni2+.
    - If that is not the case, then, usually oxygen is taken as -2, see if you can work something out from there.

    1) a peroxide comes from the fact that it is the O-O bond. ie H-O-O-H
    this is the peroxide bond. NO2 is nitrogen dioxide, O=N=O, not a peroxide. peroxide doesn't have carbon, so no C-C bond.

    superoxide is an anion of oxygen with the chemical formula O2-.
    2 is a superscript.

    Hence, 2(oxygen charge) = -1 so each oxygen has -1/2 charge
    Thank you for that
    Um no it doesn't say the Ni compound has any charge at all. Maybe a typo. I'll ask my teacher tomorrow.
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    (Original post by Phalange)
    Thank you for that
    Um no it doesn't say the Ni compound has any charge at all. Maybe a typo. I'll ask my teacher tomorrow.
    Ni has 8 electrons in its d orbitals, couples with those 8, 2 from each CO as ligand donor, That would be 16 electrons, short of the "holy grail" 18 electron rule for stable TM complex.

    Anyway, just check with your teacher. I could be wrong about this.
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    (Original post by shengoc)
    Ni has 8 electrons in its d orbitals, couples with those 8, 2 from each CO as ligand donor, That would be 16 electrons, short of the "holy grail" 18 electron rule for stable TM complex.

    Anyway, just check with your teacher. I could be wrong about this.
    Don't forget that in complex, transition metal electrons invariably sit in the valence d-orbitals in preference to the s-orbitals, so Ni0 is d10. Adding the 8 carbonyl electrons gives you the desired 18.
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    (Original post by -Kav-)
    Don't forget that in complex, transition metal electrons invariably sit in the valence d-orbitals in preference to the s-orbitals, so Ni0 is d10. Adding the 8 carbonyl electrons gives you the desired 18.
    ah, it is the desired "holy grail" after all, that is what our tutor likes to call it!
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    (Original post by shengoc)
    CO is carbon monoxide, itself has zero charge. You are probably missing the supposed 2+ for the compound Ni(CO)4, which is really Ni2+.
    As you quite correctly state the carbonyl ligand is neutral so that the oxidation state of Ni in Ni(CO)4 is zero.

    This is one of the (few) cases where a TM takes a zero oxidation state.

    On another note, this compound is important in the Mond process for purification of nickel.
 
 
 
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