Lab: Calculations for Alkalinity experiment

There seems to be some confusion about the calculations of Alkalinity test that is being performed this week.

Alkalinity in ppm (as CaCO3) = Volume of titrant used x N x 50 x1000 / Vol of sample

Here, N: normality of titrant = 0.1 N

Thus, alkalinity in ppm (as CaCO3) = Volume of titrant used x 5 x 1000 / Vol of sample

Also, if P: phenolphthalein alkalinity and T is total alkalinity, both calculated by using the above mentioned equations, then:

1) if T = 2P, Hydroxide alkalinity = bicarbonate alkalinity = 0, Carbonate alkalinity = 2P

2) if T < 2P: Hydroxide alkalinity = 2P-T, Carbonate = 2 (T-P), Bicarbonate = 0

3) if T > 2P: Hydroxide = 0, carbonate = 2P, bicarbonate = T-2P

Good luck with calculations.....