Concentration of A (H2SO4) = 0.123 mol dm⁻³

To solve this problem, we need to perform calculations based on the titration data provided. We will assume that the "average volume of A used" refers to a standard aliquot volume of $25.0 \text{ cm}^3$ for the acid in the titration.

Given:
Concentration of A ($\text{H}_2\text{SO}_4$) = $0.123 \text{ mol dm}^{-3}$
Solution B is $\text{NaOH}$
Titre value (volume of B used) = $23.6 \text{ cm}^3$
Atomic masses: H=1, O=16, S=32, Na=23
Avogadro's Constant = $6.02 \times 10^{