Roebic Laboratories, Inc. 32-oz Drain Cleaner Crystals
Read the Safety Data Sheet! You've used a very hazardous chemical, which reacts with water to get very hot. It can easily get hot enough to boil the water in the drain, causing the boiling hot caustic (able to dissolve flesh) solution to spurt out the drain, perhaps onto you! It can also get hot enough to damage pipes, particularly those of plastic, and it could then leak out into a cabinet or onto the floor.

Do NOT touch any spilled crystals or leaked liquid. If you have, wash where it touched with a lot of vinegar.

The crystals have clumped in the drain, and perhaps the best thing to do would be to fill the sink with cold water and let them dissolve, which they will do over time. Do not push anything into the drain to speed this up. If this doesn't help, call a plumber, and warn her or him what you put in the drain.