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  • ohnoez!
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    478 posts since May '07
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    tinuviel07
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    2,515 posts since Oct '07
  • kenn3th
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    17,497 posts since Nov '06
    • 21 Apr `08, 8:09PM

      An alkali is a base.

      But a base is not an alkali

      a base is an hydroxide, oxide of metal.

       

  • ohnoez!
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    478 posts since May '07
    • 21 Apr `08, 8:13PM

      why is NH3 an alkali? is it even a base?

       

      and for Ba(OH)2...why is it an alkali? is it soluble in water?

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    tinuviel07
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    2,515 posts since Oct '07
    • 21 Apr `08, 8:17PM

      ohoh.. never see alkali..

      yep as kenneth says. an alkali is a base that is soluble in water

  • kenn3th
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    17,497 posts since Nov '06
    • 21 Apr `08, 8:20PM
      Originally posted by ohnoez!:

      why is NH3 an alkali? is it even a base?

       

      and for Ba(OH)2...why is it an alkali? is it soluble in water?

      NH3 in aqueous state is alkali. It is an exception.


      Ba(oh)2 is an alkali. Just know that alkali = oh or o

      for eg: naoh (sodium hydroxide)

      No. Most metal oxides are insoluble in water.

  • ohnoez!
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    478 posts since May '07
    • 21 Apr `08, 8:28PM

      lol roflmao i am getting more confused....my teacher say Ba(OH)2 not alkali then i read textbook it says it is and that all alkali are soluble in water and now you say they dont.....lol i gonna fail chemistry liao XDXDsad.pngsad.png

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    tinuviel07
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    2,515 posts since Oct '07
    • 21 Apr `08, 8:30PM

      from what i know. an alkali is a base that dissolves in water. so yes ammonia is an alkali because it dissolves in water. base is a bigger group. but usually used to refer to insoluble bases like metal oxides.

      *sorry english typo*

      Edited by tinuviel07 21 Apr `08, 8:36PM
  • ohnoez!
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    478 posts since May '07
    • 21 Apr `08, 8:32PM

      sorry for asking so much.....wont Ba(OH)2 form a protective layer of oxide in water then wont be soluble?

      Edited by ohnoez! 21 Apr `08, 8:32PM
  • ohnoez!
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    478 posts since May '07
    • 21 Apr `08, 8:33PM
      Originally posted by tinuviel07:

      from what i know. an alkali is a base that dissolves in water. so yes ammonia is an alkali because it dissolves in water. base is a bigger group. but usually used to refer to insoluble alkalis like metal oxides.


      how can alkalis be insoluble? cry.png i thought insoluble metal oxides are just bases?

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    tinuviel07
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    2,515 posts since Oct '07
    • 21 Apr `08, 8:35PM
      Originally posted by ohnoez!:

      sorry for asking so much.....wont Ba(OH)2 form a protective layer of oxide in water then wont be soluble?

      All hydroxides are insoluble EXCEPT those of ammonium, barium and alkali metal (Group I) cations.

  • gunner77
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    13,240 posts since Apr '06
  • kenn3th
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    17,497 posts since Nov '06
  • ohnoez!
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    478 posts since May '07
  • ohnoez!
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    478 posts since May '07
    • 21 Apr `08, 8:41PM
      Originally posted by tinuviel07:

      All hydroxides are insoluble EXCEPT those of ammonium, barium and alkali metal (Group I) cations.


      lol....Ba(OH)2 react with water form wat?

       

      Ba(OH)2 + H2O ->????

       

      so ALL alkali are soluble?

  • YuutoFlow
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    374 posts since Dec '07
    • 21 Apr `08, 8:42PM

      Bee stings are acidic while wasp stings are alkali i got tt question for my chem test ... I noe NH3 is but Ba(OH)2 i dunno ...

  • kenn3th
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    17,497 posts since Nov '06
  • kenn3th
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    17,497 posts since Nov '06
    • 21 Apr `08, 8:43PM
      Originally posted by ohnoez!:


      sec 4 sad.pngsad.png


      shud be same text book

      turn to page 252 onwards read!!!!

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    tinuviel07
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    2,515 posts since Oct '07
    • 21 Apr `08, 8:44PM
      Originally posted by ohnoez!:


      lol....Ba(OH)2 react with water form wat?

       

      Ba(OH)2 + H2O ->????

       

      so ALL alkali are soluble?


      dissociates into Ba2+ and OH- ions..

      yup all alkalis are soluble. alkalis are soluble bases. bases is the general group

  • ohnoez!
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    478 posts since May '07
    • 21 Apr `08, 8:47PM

      my book pg 252 is abt rusting lol.....thx everyone for the help lol....any idea why my teacher say Ba(OH)2 is not alkali?

  • kenn3th
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    17,497 posts since Nov '06
    • 21 Apr `08, 8:47PM

      Yep, it's just like acid when reacts with water, then it turns into an acid. if not, acid in solid state will not turn damp blue litmus red

  • kenn3th
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    17,497 posts since Nov '06
    • 21 Apr `08, 8:48PM
      Originally posted by ohnoez!:

      my book pg 252 is abt rusting lol.....thx everyone for the help lol....any idea why my teacher say Ba(OH)2 is not alkali?


      no. Barium Hydroxide is an alkali.

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    tinuviel07
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    2,515 posts since Oct '07
    • 21 Apr `08, 8:48PM
      Originally posted by ohnoez!:

      my book pg 252 is abt rusting lol.....thx everyone for the help lol....any idea why my teacher say Ba(OH)2 is not alkali?


      well your teacher say wrongly? slip of the tongue perhaps

  • kenn3th
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    17,497 posts since Nov '06
    • 21 Apr `08, 8:50PM
      Originally posted by tinuviel07:


      well your teacher say wrongly? slip of the tongue perhaps


      maybe ts hear wrongly

  • ohnoez!
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    478 posts since May '07
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