Reverse Osmosis Desalination (2D)

This 2D companion strips the reverse-osmosis lab down to the physics that actually govern it: the van 't Hoff equation π = iMRT computes a genuine osmotic pressure from the feed's salt concentration and temperature, and every water or salt particle drawn on the canvas only crosses the membrane when the numbers say it should. Push the applied-pressure slider above the current osmotic pressure and clean water streams through while salt is mostly rejected; drop it below, and the net driving pressure goes negative — forward osmosis takes over and the membrane stops producing fresh water, exactly as a real RO plant would. The feed chamber concentrates as pure water is drawn off, so the osmotic pressure climbs over time even at a fixed salinity setting, and the rejection slider controls how much salt leaks through a real membrane's imperfect selectivity.