The equivalent conductivities of two strong electrolytes at infinite dilution in ${\mathrm{H}}_2\mathrm{O}$(where ions move freely through a solution) at 25 °C are given below:

${\mathrm{\Lambda }}_{{\mathrm{CH}}_3\mathrm{COONa}}^{\mathrm{\infty }}=91.0\mathrm{S}{\mathrm{cm}}^2/\text{ equiv }{\mathrm{\Lambda }}_{\mathrm{HCl}}^{\mathrm{\infty }}=426.2{\mathrm{cm}}^2/\text{ equiv }$

What additional information/quantity one needs to calculate of ${\Lambda }^{\mathrm{\infty }}$of an aqueous solution of acetic acid?