100 mL of 0.2 M K ₄[ Fe ( CN )₆] is mixed with 400 mL of 0.1 M BaCl ₂ . Assuming 100 % ionization for both the electrolytes and no chemical reaction between them, the resulting mixture is found to be isotonic with an x 10⁻² M solution of urea at the same temperature. The value of x is

Step-by-step solution

For K ₄[ Fe ( CN )₆] , assuming 100 % ionization, it dissociates into 4 K ^+ and [ Fe ( CN )₆]⁴⁻ . van 't Hoff factor, i₁ = 5 . Moles of K ₄[ Fe ( CN )₆] = 0.2 M 0.1 L = 0.02 mol . Effective moles of particles from K ₄[ Fe ( CN )₆] = i₁ n₁ = 5 0.02 = 0.10 mol . For BaCl ₂ , assuming 100 % ionization, it dissociates into Ba ²⁺ and 2 Cl ^- . van 't Hoff factor, i₂ = 3 . Moles of BaCl ₂ = 0.1 M 0.4 L = 0.04 mol . Effective moles of particles from BaCl ₂ = i₂ n₂ = 3 0.04 = 0.12 mol . Total effective moles of particles