posted by ADA .
the solubility of KNO3 is 8.9 moldm3 at 50c.what is the mass of salt would be require to saturate 200cm3 of water at this temperature.
I am going to assume that the solubility of KNO3 stated is the maximum solubility and is in water.
You need to know the molecular mass of KNO3, lets say it is M.
200 cm3 is 1/5 of a litre so the number of moles needed is
8.9 mol x 1/5 = 1.79 mol
the mass needed is then 1.79 x M