Question

The strength of 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.
B.Aq. $NaOH$ in a burette and concentrated ${H_2}S{O_4}$ in a conical flask.
C.Aq. $NaOH$ in a pipette and aqueous oxalic acid in a burette.
D.Aq. $NaOH$ in a volumetric flask and concentrated ${H_2}S{O_4}$ in a conical flask.

Answer 1

Hint: We have to know that titration (also known as titrimetry and volume analysis) is a common laboratory method for quantitative chemical analysis to determine the concentration of an identified analyte (the substance to be analyzed). The reagent, which is called a titrant or titrator, is prepared as a standard solution of known concentration and volume.

Complete answer:
Let’s first understand about titration
Titration-Titration (also known as titrimetry and volume analysis) is a common laboratory method for quantitative chemical analysis to determine the concentration of an identified analyte
Now let us understand what Acid-base titration
Acid-base titration- It relies on neutralization between acid and base when mixed in solution.
 In addition to the sample, a suitable pH indicator is added to the titration chamber, which shows the pH range of the equivalence point.
 The acid-base indicator shows the end point of the titration by changing the colour. The end point and the equivalence point are not exactly the same, because the equivalence point is determined by the stoichiometry of the reaction, whereas the end point is simply a change in the colour of the indicator.
Since sodium hydroxide is not a standard base, a standard solution of oxalic acid is prepared and used to standardize sodium hydroxide.
The reaction between sodium hydroxide and oxalic acid is ${\left( {COOH} \right)_2} + 2NaOH \to {\left( {COONa} \right)_2} + 2{H_2}O$
When a dilute oxalic acid solution is titrated with a sodium hydroxide solution, the protons react in a gradual neutralization reaction that appears with very different equivalence points on the titration curve. Oxalic acid is an example of an acid which can react with two available protons with different values ​​of Ka for the dissociation (ionization) of each proton.
In this titration we take NaOH in the burette and oxalic acid is taken in the conical flask.
Hence the correct option is (A) and options (B), (C) and (D) are incorrect.

Note:
When titrating an acid-base, the amount of acid is chemically equal to the number of bases. Titration of acids and very bases at point at the end of the solution, the solution becomes neutral.
-The case of a strong base, the weak acid conjugate base raises the pH at the equivalence point to more than $7$.
-We want the indicator to change within this pH range. Both methyl orange and bromocresol green change their colour in the acidic pH range, whereas phenolphthalein changes the alkaline pH. Hence phenolphthalein is used as an indicator in the above titration.
-Determination of the strength of an acidic solution by titration with a standard alkaline solution is called acidimetry, while the determination of the strength of a base solution by titration with a standard acid solution is called alkalimetry.