I was reading about HNO3 and I saw it can be mixed with alcohol to form "nital", which is useful when etching metals, especially carbon steel.
I wonder why alcohol is needed? HNO3 itself is corrosive for metals. So I did a little search and some college students claimed that alcohol is for holding back the reaction rate to get a better result, but it raised more questions for me... My thought now is alcohol is not as polar as water, so HNO3 would probably be less readily dissociated. But I can't figure out the rest.