How does elemental bromine oxidize the iodide ion?

1 Answer
Nov 22, 2016

Elemental bromine is reduced by iodide ion according to the following reaction:

#Br_2(aq) + 2NaI(aq) rarr I_2(s) + 2NaBr(aq)#

Explanation:

The amount of iodine formed can sometimes be determined by back-titration with sodium thiosulfate:

#I_2(s) + 2S_2O_3^(2-)rarrS_4O_6^(2-) + 2I^-#