- The porosity \( \epsilon \) is related to the specific surface area \( A_s \) and the density \( \rho \) of the catalyst by the equation: \[ A_s = \frac{6(1 - \epsilon)}{d_p \rho} \] where \( d_p \) is the average pore diameter. - Rearranging to solve for \( \epsilon \), \[ \epsilon = 1 - \frac{A_s d_p \rho}{6} \] - Substituting the values: \[ \epsilon = 1 - \frac{75 \times 8 \times 10^{-7} \times 2}{6} = 0.4 \]
Conclusion: The porosity of the catalyst is 0.4, as given by option (A).