Places to Donate
Remove the sink from the counter, thoroughly clean it and assemble all the mounting hardware such as brackets, bolts and nuts. Contact your nearest Habitat for Humanity ReStore to determine if it currently has a need for sinks.
This organization takes used home supplies and sells them to raise funds to build homes in your community. Depending on the nature and size of the sink, you can get a tax receipt for your donation.
If your region doesn't have a ReStore, seek other organizations. Goodwill and Salvation Army, while ideal for accepting numerous household items, don't often accept sinks.
Call other charities in your city that accept donations or run thrift shops to gauge their needs for your sink.