Question

Dcscribc the diKercncc bets'ccn a direct and a back titration. Why might a back
situation bc advantageous?

What is a masking agcnt, why might it bc useful in an EDTA titration ofmany
dillbrent ions?

Answer 1

In a direct titration, titrants react directly with analyte and it is used when the endpoint of the titration can easily be obtained.

In a back titration, a known excess of reagent that reacts with analyte is used. The excess is then measured with a second titrant and it is used to determine the exact endpoint when there are sharp color changes.

A masking agent is a reagent used in chemical analysis which reacts with chemical species (that protects some component of analyte from reaction with EDTA) that may interfere in the analysis .

It might be useful in an EDTA titration of dilvant ions as it protects some component of analyte from reaction with EDTA. Therefore,accuracy in the end point.