[natsuke07]

hello ! i need help.
   what is the volume relationship of standard acid used to reach phenolphthalein (Vph) and methyl orange (Vmo) endpoints when two separate titrations on identical samples, each employing a different indicator?? (component present is NaOH, NaHCO3, Na2CO3, NaOH + Na2CO3, NaHCO3 + Na2CO3)

 i already had answer in the volume relation when 2 diferent endpoints in a single titration using two different indicators:
NaOH : Vph = Vmo
NaHCO3 : Vph=0 ; Vmo=0
 Na2CO3: Vph = 1/2Vmo
 NaOH + Na2CO3 : Vph>1/2Vmo
 NaHCO3 + Na2CO3 : Vph < 1/2

how to find the other volume relationship when the other method is used,, please help ..

[Borek]

http://www.titrations.info/acid-base-titration-sodium-hydroxide-and-carbonate