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Why reducing nature of hydrides increases down a group?

  1. Feb 16, 2015 #1
    But for oxides reducing nature decreases down a group.
    We say non metallic oxides are acidic but for hydrides it is opposite,
    What's the appropriate reason?
     
  2. jcsd
  3. Feb 16, 2015 #2
    Down a group , the metal electropositivity increases and so negative charge comes up on the hydride more easily
     
  4. Feb 16, 2015 #3
    Okay but then why
     
  5. Feb 17, 2015 #4
    Are you learning p-block?
    Anyway,the bond dissociation energy for hydrides decreases down a group. So reducing nature increases
     
  6. Feb 17, 2015 #5
    Yes you are right.
    okay, the only question that remains is that why,
    ?
     
  7. Feb 19, 2015 #6

    Suraj M

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    Going down the group, wouldn't the bond between the atom and oxygen get weaker, so the atom would furnish Oxygen easily which would would actually increase oxidizing power.
    But then again, contradicting the above statement, going down the group decreases the number of O atoms(inert pair e.) on the Non metal, which would again decrease the oxidizing power of the oxide.
    And also i remember reading somewhere(NCERT) that larger the atom, more ability to stabilize the oxide ions(read it under s-block).That would mean it would decrease the oxidizing power.
    I;m a bit confused on how to consider all these factors,
     
  8. Feb 19, 2015 #7
    Please provide an example where you have the doubt
     
  9. Feb 19, 2015 #8

    Suraj M

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    Proton, could you telm me if it is true that the reducing power of oxides decreases down the group!
     
  10. Feb 19, 2015 #9
    As I said , give an exmple of the compound . Metallic and non-metallic oxides have different variations .
     
  11. Feb 19, 2015 #10

    Suraj M

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    He said p block. right?
     
  12. Feb 19, 2015 #11
    If I am not mistaken , p-block is not a compound !!
    CO is the most common OXIDE reducing agent . Do you expect Sodium oxide to behave as a good reducing agent ?
     
  13. Feb 19, 2015 #12

    Suraj M

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    Oh ok sorry.
     
  14. Feb 19, 2015 #13
    I would give example, but first tell me that does increasing reducing strength means more basicity?
     
  15. Feb 19, 2015 #14
    I think this all acidity, oxidizing strength is related.
    But not able to find the real difference between Hydrides and oxides.
    We say non metallic oxides like CO2 are acidic but MgO are basic. Why that is the case?
    I saw some sites but they give the reason of dissolving in water to form alkali for basic oxides. That's experimental and not a logic by theory.
    This was taught in our school but theoretical logic was not given.
    We say down the group basic nature of oxides increase for any group not only taking p block but all groups.
    For hydrides that is opposite, why ?
    I expect NaO to be a oxidizing agent.
     
    Last edited: Feb 19, 2015
  16. Feb 19, 2015 #15
    basicity of hydrides decreases down the group in group 15 and 16 . Missed out the ones
     
    Last edited: Feb 19, 2015
  17. Feb 19, 2015 #16
    You mean the d block?
     
  18. Feb 19, 2015 #17
    I edited the post
     
  19. Feb 19, 2015 #18
    But why only 15- 16?
     
  20. Feb 19, 2015 #19
    Proton007007 asked for a compound above (maybe) because all groups dont have hydrides with lone pair .
    I said 15 and 16 as they have lone pairs to donate and qualify as Lewis Base .
     
  21. Feb 19, 2015 #20
    So what about group 17 of halogens. They also have lone pair.
    Acidity for hydrides of halogens increases down the group. Like HI>HBr>HCl>HF
    Here also basicity is decreasing down the group.
     
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