Is it possible to use sound blaster for chatting

You will need to disable onboard audio in the BIOS first.
Then you will need to plug the mic into the SB card. Also, you will need to set the default recording device to Mic SB xxxx series.
After that when you configure/reconfigure the Audio Input settings in the chat or messenger applet it will allow you to use the SB as the default audio device on the PC.