50 mL of a solution containing 1 g each of `Na_(2)CO_(3), NaHCO_(3)` and NaOH was titrated with N-HCl. What will be the titre reading when only phenolphalein is used as indicator?

Options

A. 35 ml
B. 32.5 ml
C. 24.5 ml
D. 34.4 ml

Answer

D

Explanation

At the end point using phenolphthalein as indicator uses complete NaOH and `(1)/(2)` Meq. of `Na_(2)CO_(3)`.
`:.` Meq of `NaOH + (1)/(2) "Meq of " Na_(2)CO_(3) = "Meq of HCl"`
`(1)/(40) xx 1000 + (1)/(2) xx (1)/(106) xx 2 xx 1000 = V xx 1 :. V = 34.4 ml`