The van't Hoff factor (i) for a dilute solution of K2SO4 in water is:
Correct: C
K2SO4 dissociates into 2 K+ ions and 1 SO42- ion in water. Therefore, i = 1 + (n-1)α, where n is the number of ions produced (3 in this case) and α is the degree of dissociation. Assuming complete dissociation (α=1), i = 3.