Cal Dershowitz wrote:
Hi NG,

This page shows a couple areas of tile adhesive I'm removing:

This area had normal ceramic tile on it, so this might be thinset.
Here, I might think of water, water with a base, water with acid,
maybe mineral spirits. Your thoughts? TIA

Thinset is cementatious. Acid will eat it. It will also eat whatever the
thinset was applied to. The other liquids you mentioned will do nothing.

Your best option is a chisel and hammer.