# The strength of an aqueous NaOH solution is most accurately determined by titrating:

Question:

The strength of an aqueous $\mathrm{NaOH}$ solution is most accurately determined by titrating: (Note: consider that an appropriate indicator is used)

1. Aq. $\mathrm{NaOH}$ in a pipette and aqueous oxalic acid in a burette

2. Aq. $\mathrm{NaOH}$ in a burette and aqueous oxalic acid in a conical flask

3. Aq. $\mathrm{NaOH}$ in a burette and concentrated $\mathrm{H}_{2} \mathrm{SO}_{4}$ in a conical flask

4. Aq. $\mathrm{NaOH}$ in a volumetric flask and concentrated $\mathrm{H}_{2} \mathrm{SO}_{4}$ in a conical flask

Correct Option: , 2

Solution:

Oxalic acid is a primary standard solution whereas $\mathrm{H}_{2} \mathrm{SO}_{4}$ is a secondary standard solution. So it does not matter whether oxalic acid is taken in a burette or in conical flask. Therefore accurate measurement of concentration by titration depends on the nature of the solution.