Say I have a rocky airless world with size and density to produce two gees orbiting around an old dim star.
Could I have a round(ish) lake with a high molar hydrochloric acid ice? It could be deposited there by collision or leftover from a long ago history. I would like this lake to rotate slowly, could be as slow as one turn per month or even one a year. Also would like the lake wobble. I am thinking a moon or a few to create the necessary tidal forces? Could a lake like this persist?
And if this lake was near a mineral deposit, could the acid leach away impurities and leave behind a near pure source of tantalum?