Adsorption of hydrogen gas over palladium surface obey Freundlich's adsorption isotherm, as shown in — Surface Chemistry Chemistry Question
Question
Adsorption of hydrogen gas over palladium surface obey Freundlich's adsorption isotherm, as shown in the graph. The mass (in g) of hydrogen gas adsorbed on the surface of 1.0 g palladium at a pressure of 8.1 × 10⁻³ atm, is<br><br>[Graph description: A linear plot of log₁₀(x/m) on the y-axis versus log₁₀P on the x-axis. The line has a y-intercept of 1.0 and a slope indicated by tanθ = 0.25]
💡 Solution & Explanation
According to the Freundlich adsorption isotherm: log₁₀(x/m) = log₁₀K + (1/n)log₁₀P. From the given graph, the y-intercept is log₁₀K = 1.0, so K = 10. The slope is 1/n = tanθ = 0.25 = 1/4. The equation becomes x/m = K·P^(1/n) = 10 × P^(1/4). Given P = 8.1 × 10⁻³ atm = 81 × 10⁻⁴ atm, we have x/m = 10 × (81 × 10⁻⁴)^(1/4) = 10 × (3 × 10⁻¹) = 3. Since mass of palladium m = 1.0 g, the mass of hydrogen adsorbed x = 3 g. Therefore, correct answer is 3.