Phenolpthalein alkalinity is also known as

A. Pure alkalinity

B. Carbonate alkalinity

C. Natural alkalinity

D. Impure alkalinity

Answer: Option B

Solution(By Examveda Team)

Phenolpthalein alkalinity is also known as Carbonate alkalinity.
The alkalinity in a water sample is measured by the amount of standard acid required to lower the pH to a level of 8.3, as indicated by the change in colour of phenolphthalein from pink to clear.
Phenolphthalein alkalinity is determined by titration to a pH of 8.3 and indicates the total hydroxide and half the carbonate present.