Oak trees have a MASSIVE root system that you are containing. Therefore the tree will not be its strongest and healthiest. I see you ask this question 6 years ago so it may already have died.

Not all species of oak require the months of cold stratification. It’s either pin oaks or White Oaks. I’ve been having trouble finding viable acorns. So awesome that you have and that you’re doing this with your students

I have collected 17 acorns which I want to plant in pots to sprout and grow over the winter then transplant to the ground in the spring. What steps should I follow

You’ll get the best result with the refrigerator. The freezer will kill them dead. The unheated garage would be second best, but the temperature will be variable, some may freeze, warm snaps may make them rot or sprout prematurely. Believe me the refrigerator is best.

That’s where the root & shoot emerge. Plant them with the pointy end facing sideways.

If the leaves turn yellow except for green veins, it’s probably chlorosis due to lack of iron or too high pH. I’m running into the beginning stages of the same issue and started them on a houseplant fertilizer with chelated iron and add a few tablespoons of vinegar to the water. Hopefully that will solve the problem.