Zinc chromate is mainly used in paints or primers to protect metals from corrosion, although it is considered a potential carcinogen and therefore needs to be controlled in the industry.
A paint sample contains this compound. To determine the amount of this substance by means of a potentiometric technique, a battery with a silver cathode and a saturated calomel anode that can be used to measure changes in ion concentration was used.
For this purpose 10.076 g of this preparation were weighed and dissolved with turpentine in 25mL. 10 mL of this solution was made up to 250 mL.
What will be the concentration of zinc chromate (%) in the paint if the battery develops a potential of 298.2mV at the last dilution?
Data: E0(Ag+/Ag)= 0.799V, KPS (Ag2CrO4 )=2.4 10-12 ; E(ECS)=0.244V.