I have a group of students who want to mix hydrogen peroxide with calcium chloride to extend from mixing the cal. Chloride with water. Is this safe, mixing the peroxide with the calcium chloride?
Thank You, Rob

Yes you can, but nothing much is 100% safe, and some mixtures release undesirable compounds or gasses into the air.
Google hydrogen peroxide + calcium chloride for all the many instructions and reasons.
Be sure to read Wiley Guide to Chemical Incompatibilities (https://books.google.com/books?id=KDHDeApHKjgC&pg=PA244&lpg=PA244&dq=peroxide+%2B+calcium+chloride&source=bl&ots=UDvomHmOep&sig=LcxhvQTR6jQd2E6b2gHPTt7sjWw&hl=en&sa=X&ved=0ahUKEwisqM_U48_TAhVL4SYKHcbaDyAQ6AEIVjAJ)
Why do they want to do this? I take it you aren't a chemistry teacher.

http://extension.psu.edu/food/safety/farm/mushrooms/good-agricultural-practices-for-safe-mushroom-production-research-recommendations-and-teaching-materials/peroxide-mushroom.pdf

Pretty long read.