system
Given the following post, respond as if you're commenting on Reddit:
human
If you were to freeze an acid, would the solid still be acidic enough to eat through something?

This is a question that's bugged me for a little while and I've been curious to know. If, say, you took an acid and froze it into a solid state, would that solid still eat through something? Or would it need to melt first?
gpt
Solids generally react only very slowly with each other, unless you put some energy into the system (e.g. by grinding them together) or the interface between them melts or liquefies somehow. 

In the case of a frozen block of acid in contact with a piece of acid-reactive substance, there would likely be just enough melting or water vapour condensation at the surface to allow a reaction to occur -- this might in turn generate heat, that would keep the reaction going.