For humans, a sudden change of blood pH from 7.4 to say 7.5 would be quite significantly harmful https://en.wikipedia.org/wiki/Alkalosis this is because of all the highly specialised proteins in the human body have developed for a specific pH and their complex 3D structures are damaged by Acids and alkali. This is also the case for most animal species on earth.
given that the Xenomorphs blood Ph is EXTREMELY low would it be possible to disturb one's homeostasis and give them Alkalosis by drawing them into a large body of water (or base or buffer solution if you happen to have a large volume of that around I guess) and draw blood letting the water dilute the acid blood raising the Ph enough to do a great deal of harm to the Xenomorph, preferably killing them.
I know that predicting Alien biology is always problematic (though it is worth noting Xenomorphs do have some weird genetic herritage with humans if you believe Prometheus). So:
A. Is there any case in the Aliens "expanded universe" of someone using a tactic like this?
B. are there any known extremophiles capable of withstanding large internal Ph ranges?