During the titration of a mixture of `Na_(2)CO_(3)` and `NaHCO_(3)` against HCl

Options

A. Phenolphthalein can be used to detect to detect the end point when half equivalent of `Na_2CO_3 ` and full equivalent NaOH is consumed (first end point)
B. Phenolphthalein can be used to detect the second end point
C. Methyl orange can be used to detect the final end point
D. Methyl orange can be used to detect the first end point

Answer

A, C

Explanation

Phenolphthalein cannot be used for weak base titration hence cannot detect `NaHCO_3` end point. Methyl arange can be used and can only detect final end point.