Should one pronounce “periodic” the same in “periodic acid” and “periodic table”?
I am an Australian English speaker and yes, this distinction is made in practice.

Possibly the only reasonable opportunity to use the pɪə pronunciation in the name of a compound is in the case of the entertaining molecule periodane, which is actually named after the periodic table. This molecule (and later a number of different plausible isomers) was identified computationally by a methodology called 'mindless chemistry' which optimises randomly generated molecular graphs. Periodane is a stable configuration of each atom on the second row of the periodic table, with the exception of neon (although some people are working on that).