Given data

• Concentration: $C = 0.8\,\text{M} = 0.8\,\text{mol L}^{-1}$
• Resistivity: $\rho = 5 \times 10^{-3}\,\Omega\,\text{cm}$

Find conductivity

Conductivity is the reciprocal of resistivity: $\kappa = \frac{1}{\rho} = \frac{1}{5\times 10^{-3}} = 200\,\Omega^{-1}\text{cm}^{-1}$

Use formula for molar conductivity

$\Lambda_m = \kappa \times \frac{1000}{C}$

Substituting values: $\Lambda_m = 200 \times \frac{1000}{0.8}$

$\Lambda_m = 200 \times 1250 = 250000\,\Omega^{-1}\text{cm}^2\text{mol}^{-1}$

Match with required format

We need to write: $\Lambda_m = \underline{\hspace{1cm}} \times 10^4\,\Omega^{-1}\text{cm}^2\text{mol}^{-1}$

Since $250000 = 25 \times 10^4$

the required integer is: $\boxed{25}$

Comparison with stored answer

Stored correct answer = $25$

This matches our derived answer.