Pesach Questions

Some items are ok to have or mix before Pesach, but not allowed if bought on Pesach. Which items are these, and why are they in this unique category? Thanks so much!

Are you referring to things like milk and eggs?     In general, chametz (like other substances) is nullified 1:60 in mixtures. But if the mixture occurs on Pesach itself, the law is stringent, and the chametz is not nullified at all.

RYK

Yes, I was referring to lactaid etc, which can be put into milk before Yom Tov, but not on Pesach. Now I understand why. Thanks for everything you're doing to help!!!!!