Add 2 drops of methyl orange indicator to 50 or 100 cc. of the sample,
or to the solution to which phenolphthalein has been added, in a white
porcelain casserole or an Erlenmeyer flask over a white surface. If the
solution becomes yellow, hydroxide, normal carbonate, or bicarbonate is
present. Add N/50 sulfuric acid from a burette until the faintest pink
coloration appears. The methyl orange alkalinity in parts per million of
calcium carbonate is equal to the total number of cubic centimeters of
N/50 sulfuric acid used multiplied by 20 if 50 cc. of the sample was
used, or by 10 if 100 cc. was used.