posted by hey .
calculate the weight of crystal formed on cooling 80 gm of saturated solution from 60 degree Celsius to 30 degree Celsius. solubility of salt at 60 degree Celsius and 30 degree Celsius are 132 and 95 respectively.
132 WHAT and 95 WHAT? If that is 132 grams of solution and 95 grams of solution, then you do it this way.
grams salt in 80 g soln at 60 C is
132 x (80/100) = about 106 but you need to do that more accurately.
When cooled to 30 C it will dissolve
95 x (80/100) = about 74 (more accuracy needed).
How much will ppt? 106-74 (or whatever your numbers turn out to be).