Subject: Inorganic Chemistry · Chapter: Analytical Chemistry · Topic: Analytical Chemistry – General · Exam: NET JUNE 2019 · Marks: 2 · Difficulty: Medium
The role of $\mathrm{H}_{3} \mathrm{PO}_{4}$ in the estimation of Fe (II) with $\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$ using diphenylamine sulphonate as ndicator is to
(a)avoid aerial oxidation of Fe(II)
(b)reduce the electrode potential of $mathrm{Fe^{3+} ext{-}Fe^{3+}}$