Which can be used as a standard solution in neutralization titrations?
a. Na2CO3
c. CH3COOH
b. NaHCO3
d. NaOH
After reading all of the responses I am of the opinion that the question asks about what solutions that previously have been standardized (by whatever means) CAN (not what is the best) be used for neutralization titrations. ANY of those listed CAN be used. As a second thought, yes, I would like to know what the author meant. Also, I might suggest that the question itself could be rewritten so as not to be misinterpreted.
I would say d.
Depends upon what you mean by a standard solution.
If you mean by standard solution a "primary standard" then I would go with NaHCO3. That's the only one in the list that can be weighed out from a bottle (after heating in an oven to dry it) and it is known purity of 100%. NaOH pellets pick up CO2 and water from the air, even in in a closed bottle, so that is not a primary standard. Na2CO3 CAN be used as a primary standard if it is heated (I THINK is is 170 C for a couple of hours to make NaHCO3). Acetic acid varies all over the map and isn't a primary standard. NOW, if you just want use a standardized material to neutralize another, then any of those materials may be used. But each, except NaHCO3 or Na2CO3 treated as I've said, must be standardized first with a primary standard.