Question

Write the reaction between indicator potassium chromate and agno3 solution

Answer 1

Basically colored ppt.$k_{2}$$CrO_{4}$ is used as a indicator.

When $AgNO_{3}$is added to a solution which contains chloride ion in the form of white colored ppt of Agcl is formed.

Then the reaction between the indicator(potassium chromate) and agno3 is given below:

$Ag^{+}$+$Cl^{-}$→Agcl

$2Ag^{+}$+$CrO_{4} ^{-2}$→$Ag_{2}$$CrO_{4}$

This procedure is used only in case of neutral solutions as silver chromate is  soluble in acids.

And in alkaline solutions silver hydroxide precipitates .

silver chromate which gives erroneous result in both cases.