Question

the solubility of a compound is 59 g / 100 ml in boiling methanol and 30 g / 100 ml in cold methanol. how much mass would you recover if you take 59g of compound and dissolve it in 100 ml of methanol and then cool it down to 0°c and filter it.

Explanation:

Step1: Identify solubility at different temperatures

The solubility in boiling methanol is 59 g/100 mL and in cold methanol is 30 g/100 mL.

Step2: Determine the amount of undissolved compound

We start with 59 g of compound in 100 mL of methanol. When cooled, the amount that can remain dissolved is 30 g (solubility in cold methanol). So the amount recovered is the initial amount minus the amount that remains dissolved.
$59 - 30=29$

Answer:

29 g