Chemistry QA

• SBS n SMRT

  26 Sep 09, 21:14

  First of all, thanks all for helping

  I have some doubts on chem for clarification

  1. For QA on aluminium nitrate with aqueous sodium hydroxide

  A ppt will be form which dissolve. the chemical equation is like this one right.

  NaOH (aq) + Al(NO3)3 (aq) --> Al(OH)3 + H20 

  Al(OH)3 +NaOH --> ???

  why the ppt will dissolve

  2. Why transitional metals will have catalytic properties

  Thanks

• dkcx

  26 Sep 09, 21:19

  Originally posted by SBS n SMRT:

  First of all, thanks all for helping

  I have some doubts on chem for clarification

  1. For QA on aluminium nitrate with aqueous sodium hydroxide

  A ppt will be form which dissolve. the chemical equation is like this one right.

  NaOH (aq) + Al(NO3)3 (aq) --> Al(OH)3 + H20 

  Al(OH)3 +NaOH --> ???

  why the ppt will dissolve

  2. Why transitional metals will have catalytic properties

  Thanks

  Al(OH)3 + NaOH -> Na+ [Al(OH)4]-

  Regarding transition elements, i think it has something to do with their multiple charge system but i 4got how it works. I don't think O's need know this anyway.

• SBS n SMRT

  26 Sep 09, 21:21

  thanks...btw, Al(OH)4 is soluble??, i thought all hydroxides are insoluble except Gp I and ammonium cmpds

• dkcx

  26 Sep 09, 21:22

  Originally posted by SBS n SMRT:

  thanks...btw, Al(OH)4 is soluble??, i thought all hydroxides are insoluble except Gp I and ammonium cmpds

  It is in ionic form as a [Al(OH)4]- anion and not a compound. This is soluble

• SBS n SMRT

  26 Sep 09, 21:24

  oh.thanks, extra electron fm OH- ion right

  thanks a lot

• Darkness_hacker99

  27 Sep 09, 15:03

  Out of the topic...

   

  Do note that Aluminium hydroxide is an amphoteric oxide which can react with both acid and alkali. Students need not not know the formula of the compound formed when amphoteric oxide react with acids/alkalis, the concept is important. 

• SBS n SMRT

  28 Sep 09, 19:14

  yes...i am aware