Answer to Question #290013 in Physical Chemistry for Jose

Question

A 50.00 mL water sample is titrated to the phenolphthalein end-point with 5.00 mL of 0.02 N H2S0 4 , and to the methyl orange end-point with additional 5.00 mL of the acid. What is the total alkalinity, in mgCaC03 /L?

Answer 1

Total alkalinity is measured by collecting a water sample, and measuring the amount of acid needed to bring the sample to a pH of 4.2. At this pH all the alkaline compounds in the sample are "used up." The result is reported as milligrams per liter (mg/l) of calcium carbonate. and pH less than 5.0.