Resistance of $0.2\,\text{M}$ solution of an electrolyte is $50\,\Omega$. The specific conductance of the solution is $1.4\,\text{S m}^{-1}$. The resistance of $0.5\,\text{M}$ solution of the same electrolyte is $280\,\Omega$. The molar conductivity of the $0.5\,\text{M}$ solution of the electrolyte in $\text{S m}^2\,\text{mol}^{-1}$ is: