Never use any chemicals to unclog a sink tub or toilet.  Most of the buildings have older plumber that chemicals will damage.

If your toilet is clogged try to use a plunger to unclog it.  If you are unsuccessful submit a maintenance request.

If your sink or tub is clogged try to remove hair or other objects from the drain.  If you are unsuccessful submit a maintenance request.

If water is overflowing out of your sink, toilet, or tub call the emergency maintenance number immediately.