The phenol content of water downstream from a coking furnace was determined by coulometric...

The phenol content of water downstream from a coking furnace was determined by coulometric analysis. A 100-mL sample was rendered slightly acidic, and an excess of KBr was introduced. To produce Br2 for the reaction

a steady current of 0.0503 A for 6 min and 22 s was required. Express the results of this analysis in terms of parts of C6H5OH per million parts of water. (Assume that the density of water is 1.00 g/mL.)