For isotonic solution: \[ i(\text{glucose}) = i(\text{K}_2\text{SO}_4) \] \[ 0.01 = i(\text{K}_2\text{SO}_4) \times 0.004 \] \[ i(\text{K}_2\text{SO}_4) = \frac{0.01}{0.004} = 2.5 \] Now, for \( K_2SO_4 \): \[ i = 1 + (n-1) \] \[ 2.5 = 1 + (n-1) \] \[ n = 3 \text{ for } K_2SO_4 \] Percentage dissociation: \[ \alpha = \frac{3}{2} = 75\% \] Thus, the percentage dissociation of K_2SO_4 is 75%.