[GAlexan468]

I am stuck on one problem in chemistry please help?  A 25ml sample of vinger deluted with water to a final volume of 250ml.  A 25ml portion of deluted vinger is titrated with 0.0998ml NAOH.  If 22.43ml of NAOH are required to each equalvent points what was the orginal concentration of acitic acid in the vinger?

CH3 CO2 2H (AQ + OH AQ) YIELDS CH3 CO2 (AQ) + H20

[Tetrahedrite]

First find the concentration of the dilute sample.

Moles NaOH required to reach end point =cV
                                                         =0.0998 X 0.02243                      
                                                         =0.002239 moles of NaOH


As the NaOH reacts with the acetic acid in a 1:1 ratio,
Moles acetic acid also = 0.002239 moles
As the volume of acid used was 25mL
conc. of acid = n/V
                =0.002239/0.025
                =0.0895M acetic acid
As the original solution was diluted by a factor of ten, the concentration of the original is 0.895M