Chemistry - Mole Concept Question with Solution | TestHub

Assertion : In the mixture of ${\mathrm{NaHCO}}_3$ and ${\mathrm{Na}}_2{\mathrm{CO}}_3$, volume of a given HCl solution required is X ml with phenolphthalein indicator and further Y ml is required with methyl orange indicator. Hence volume of HCl required for complete neutralisation of ${\mathrm{NaHCO}}_3$ is $(\mathrm{Y}-\mathrm{X})\mathrm{ml}$.

Reason : With phenolphthalein indicator, the end point appears when Na₂CO₃ is converted to NaHCO₃; while with methyl orange, the end point appears when H₂CO₃ is formed.