Step 1: Molar conductivity formula.
Molar conductivity is the conductivity of a solution per mole of solute. The formula for molar conductivity is:
\[
\Lambda_m = \kappa \times V
\]
where \( \kappa \) is the conductivity and \( V \) is the volume of the solution.
Step 2: Conclusion.
Thus, the formula for molar conductivity is \( \Lambda_m = \kappa \times V \).