Nomen Nescio wrote:


Question: Why doesn't the same pressure effect occur for the freezing
point?



The vapor pressure of ice (and ice -water mix) is effectively 0.


Irrelevent! The melting point involves an equilibrium between the
solid ice and the liquid
water. The vapor is totally irrelevent (except at the triple point,
where all three phases
are in equilibrium).

Rich Lemert