Alkalinity Testing

“P” All the OH and half of the Carbonate, “T” Total Alkalinity rest of the carbonate and all of the Bicarbonate, OH is calculated 2P – T = OH
- For the P test, add Phenolphthalein to sample, titrate to color change pink to clear. Record P.
- To the same sample add Total Alkalinity indicator. Sample turns green. Titrate to red. Record T.
- OH = 2P-T
- A more accurate OH would be to add BaCl to sample. Add Phenolphthlein. Titrate pink to clear.