i didn't mean 'the idea that chemistry is not part of software'

'tech' is short for 'technology' in the oed's sense 1b, 'practical arts collectively', for which their first citation is from 01859, referring to, as it happens, chemistry; specifically, the formulation of varnishes for wood

https://archive.org/details/oed9barch/page/n548/mode/1up

possibly also the second half of their sense 1a, '... the scientific study of the practical or industrial arts,' for which i think the first citation is from bentham in 01802–12

obviously in the 19th century they weren't talking about software

your idea is good though

i hope you do it