They use information from other things that relate to that topic and then use that to do their research
Answer is: osmotic pressure.
Osmotic pressure, alongside the vapor pressure depression, freezing point depression and the boiling point elevation are<span> the </span>colligative properties od solution.
<span>The direction of osmotic pressure is always from the side with the lower concentration (c = n/V) of solute to the side with the higher concentration.</span>
2AgCl (s) + Ba(NO3)2 (aq)