The strength of an aqueous NaOH solution is most accurately determined by titrating : (Note : consider that an appropriate indicator is used)
- (A)Aq. NaOH in a burette and aqueous oxalic acid in a conical flask✓ Correct
- (B)Aq. NaOH in a pipette and aqueous oxalic acid in a burette
- (C)Aq. NaOH in a volumetric flask and concentrated in a conical flask
- (D)Aq. NaOH in a burette and concentrated in a conical flask
Answer: (A)
Solution
For a reliable determination of the strength of sodium hydroxide, the alkali to be standardized is taken in the burette while the primary standard, aqueous oxalic acid, is placed in the conical flask, so that the titrant volume is measured precisely. A concentrated acid cannot serve here because it is hygroscopic and is not a primary standard.
JEE Main · 2020 · 08 Jan 2020 · Shift 1 · Single correct option