Final answer:
The correct answer is a) HCl because it has the larger equilibrium constant for acid ionization, indicating that it is a stronger acid compared to HOCl, hence resulting in a greater freezing point depression.
Step-by-step explanation:
When equal molar amounts of HCl and HOCl are dissolved separately in equal amounts of water, the solution of HCl freezes at a lower temperature. This is because HCl is a strong acid and dissociates completely in water into H+ and Cl- ions, which increases the number of particles in solution and therefore the freezing point depression is greater.
HOCl, on the other hand, is a weak acid and does not dissociate completely, resulting in fewer ions in solution and a smaller effect on the freezing point.
The larger the equilibrium constant for acid ionization, the stronger the acid and the more it dissociates into ions. Since HCl dissociates more, it has a larger equilibrium constant (K_a) compared to HOCl.
Therefore, the correct answer is a) HCl because it has the larger equilibrium constant for acid ionization.