Why must we add sodium bicarbonate (NaHCO3) to DCPIP/DPIP indicator (Dichlorophenol indophenol)when titrating juice for Vitamin C?

2 answers

The indicator does not work well in an acid medium. NaHCO3 is used as a buffer to maintain an alkaline pH of about 9. For more information, see the link below:

http://www.cforyourself.com/Overview/Primer/Chemistry/c_tests.html
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