Quantitative analysis of soda ash by double indicator

Question

*why there is a need to boil distilled water in the preparation of base solutions?

*why a mixture of NaOH and NaHCO3 is incompatible?

*why there is a need t o boil the solution before reaching the methyl orange endpoint?

*is it possible to used NaOH as primary standard for HCl and the properties of an ideal primary standard?

*what is the rationale behind not storing basic solutions in volumetric glassware?

Answer 1

*why there is a need to boil distilled water in the preparation of base solutions?

*why a mixture of NaOH and NaHCO3 is incompatible?

*why there is a need t o boil the solution before reaching the methyl orange endpoint?
You want to rid the water of CO2 from H2O + CO2 ==> H2CO3.

*is it possible to used NaOH as primary standard for HCl and the properties of an ideal primary standard?
No, NaOH is sold commercially and it is relatively pure (probably 98 or 99% or better); however, it picks up water plus CO2 from the air and that makes unsuitable for use as a primary standard.

*what is the rationale behind not storing basic solutions in volumetric glassware?
Strong bases react with the SiO2 in glassware.

Answer 2

I see I missed a couple

*why there is a need to boil distilled water in the preparation of base solutions?
Same a below. You want to rid the solution of CO2 that is dissolved in the water.

*why a mixture of NaOH and NaHCO3 is incompatible?
I don't know that I would call them incompatible. They are incompatible in the the sense that they react with one another but they are not incompatible because of an explosion or some other deleterious effect.
NaOH + NaHCO3 ==> Na2CO3 + H2O
In other words, you no longer have NaOH and NaHCO3. You have water and Na2CO3.