Sometime ago, gtalk quit working in Pidgin.
This assumes you have Pidgin and the facebook chat module installed:
sudo apt-get install pidgin
If you add an account. It just never connects. At least not for me. This was the work around I found.
This is an OLD SCHOOL fix. This was straightforward for me, but it may not be for you
Here’s the word explanation:
1. Hit the advanced tab.
2. Change the port to 443.
3. Change the connect server to talk.google.com
4. Hit save.
And what it should look like when you are done!