At a given temperature, 0.45 g of acetic acid in 50 mL of water is shaken with 1.0 g of charcoal and the pH of the resulting solution is 3.0. Assume, the adsorption of acetic acid from the aqueous solution by charcoal follows Freundlich isotherm, x/m = kC¹⁄ⁿ. If the plot of log₁₀(x/m) against log₁₀C gives a straight line with slope 1, the value of k in L mol⁻¹ is ____ . Given: The molar mass of acetic acid is 60 g mol⁻¹. The acid dissociation constant of acetic acid is 1.0 × 10⁻⁵ at the given temperature. x is the mass (in grams) of acetic acid adsorbed; m is the mass (in grams) of charcoal; C is the equilibrium concentration of acetic acid in the solution after the adsorption is complete; k and n are constants for acetic acid–charcoal system at the given temperature.