Question

Consider separate aqueous solution of $\mathrm{HCl}$and ${\mathrm{H}}_2{\mathrm{SO}}_4$each with the same molar concentration. An aqueous solution of $\mathrm{NaOH}$ is added to each solution to neutralize the acid. Which acid solution requires the largest volume of $\mathrm{NaOH}$solution to react completely with the acid present? Explain.

Short answer

$H_{2}S{O}_4$acid is required greater volume$NaOH$ to react completely, because of hydrogen ions present in $H_{2}S{O}_4$acid.

Step-by-step solution

Neutralization of HCl by NaOH.

$HCl + NaOH \to NaCl + H_{2}O$

In the reaction

$\text{Moles} \text{of} \text{NaOH} \text{required=10} \text{moles} \text{of} \text{HCl×}\frac{\text{1} \text{mol} \text{NaOH}}{\text{1} \text{mol} \mathrm{HCl}}$

$\text{Moles} \text{of} \text{NaOH} \text{required} =\text{10} \text{mol} \text{NaOH}$

$\text{Volume} \text{of} \text{NaOH} \text{required=10} \text{moles} \text{NaOH×}\frac{\text{1.0LNaOH}}{\text{10.0} \text{moles} \text{NaOH}}$

$\text{Volume} \text{of} \text{NaOH} \text{required} =\text{1.0LNaOH}$

Neutralization of H2SO4 by NaOH.

$H_{2}S{O}_4 + 2NaOH \to N{a}_{2}S{O}_4 + 2H_{2}O$

In the reaction

Moles of $NaOH$required$=20 \text{mol} NaOH$

Volume of $NaOH$required$=2.0L NaOH$

Conclusion

Therefore,$H_{2}S{O}_4$acid requires higher volume of$NaOH$ to react completelywith it. Because of the presence of two moles of hydrogen ions in acid$H_{2}S{O}_4$.