In the mixture of `(NaHCO_(3) + Na_(2)CO_(3))`, volume of HCl required is x mL with phenolphthalein indicator and y mL with mthyl orange inidicator in same titration. Hence, volume of HCl for complete reaction of `Na_(2)CO_(3)` is :

Options

A. 2 x
B. y
C. `x//2`
D. `(y-x)`

Answer

A

Explanation

In pressure of phenolphthalein, `50% Na_(2)CO_(3)` is neutralised whereas `NaHCO_(3)` remains unaffected. In presence of methyl orange, both `Na_(2)CO_(3) " and" NaHCO_(3)` will be 100% neutralised.
Let volume of HCl for complete reaction of `Na_(2)CO_(3)=V_(1)` mL and volume of HCl for complete reaction of `NaHCO_(3)=V_(2)` mL . With phenolphthalein, `50% Na_(2)CO_(3)` will be neutralized.
`therefore " " (V_(1))/(2)=x, V_(1)=2x`