Question

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?
A. (a)35 mL
B. (b)32.5 mL
C. (c )24.5 mL
D. (d)34.4 mL

Answer 1

Correct Answer - d
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
`1/40xx1000+1/2xx1/106xx2xx1000=Vxx1`
`:. V=34.4 ml`